U.S. patent application number 13/881268 was filed with the patent office on 2013-11-07 for star macromolecules for personal and home care.
This patent application is currently assigned to ATRP Solutions, Inc.. The applicant listed for this patent is Wojciech Jakubowski, Patrick McCarthy, James Spanswick, Nicolay Tsarevsky. Invention is credited to Wojciech Jakubowski, Patrick McCarthy, James Spanswick, Nicolay Tsarevsky.
Application Number | 20130296495 13/881268 |
Document ID | / |
Family ID | 45994702 |
Filed Date | 2013-11-07 |
United States Patent
Application |
20130296495 |
Kind Code |
A1 |
Jakubowski; Wojciech ; et
al. |
November 7, 2013 |
Star Macromolecules for Personal and Home Care
Abstract
A polymer composition comprising star macromolecules is
provided. Each star macromolecule has a core and five or more arms,
wherein the number of arms within a star macromolecule varies
across the composition of star molecules. The arms on a star are
covalently attached to the core of the star; each arm comprises one
or more (co)polymer segments; and at least one arm and/or at least
one segment exhibits a different solubility from at least one other
arm or one other segment, respectively, in a reference liquid of
interest.
Inventors: |
Jakubowski; Wojciech;
(Pittsburgh, PA) ; McCarthy; Patrick; (Pittsburgh,
PA) ; Tsarevsky; Nicolay; (Dallas, TX) ;
Spanswick; James; (Pittsburgh, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jakubowski; Wojciech
McCarthy; Patrick
Tsarevsky; Nicolay
Spanswick; James |
Pittsburgh
Pittsburgh
Dallas
Pittsburgh |
PA
PA
TX
PA |
US
US
US
US |
|
|
Assignee: |
ATRP Solutions, Inc.
Pittsburgh
PA
|
Family ID: |
45994702 |
Appl. No.: |
13/881268 |
Filed: |
October 26, 2011 |
PCT Filed: |
October 26, 2011 |
PCT NO: |
PCT/US11/57789 |
371 Date: |
July 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12926143 |
Oct 27, 2010 |
8173750 |
|
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13881268 |
|
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|
|
12799411 |
Apr 23, 2010 |
|
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12926143 |
|
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|
61214397 |
Apr 23, 2009 |
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Current U.S.
Class: |
525/242 |
Current CPC
Class: |
C08G 83/003 20130101;
A61K 8/8152 20130101; A61K 2800/10 20130101; A61K 2800/48 20130101;
C08F 299/0492 20130101; A61Q 19/00 20130101; C08F 265/04 20130101;
C08F 2438/01 20130101; A61K 8/72 20130101; C08F 299/04 20130101;
C08J 2300/206 20130101; A61K 8/8147 20130101; A61K 8/90 20130101;
C08F 293/005 20130101 |
Class at
Publication: |
525/242 |
International
Class: |
C08F 265/04 20060101
C08F265/04 |
Claims
1. A star macromolecule represented by Formula X:
[(P1).sub.q1-(P2).sub.q2].sub.t-Core-[(P3).sub.q3].sub.r Formula X
wherein: Core represents a crosslinked polymeric segment; P1
represents a homopolymeric segment comprised of repeat units of
monomeric residues of polymerized hydrophobic monomers; P2
represents a homopolymeric segment comprised of repeat units of
monomeric residues of polymerized hydrophilic monomers; P3
represents a homopolymeric segment comprised of repeat units of
monomeric residues of polymerized hydrophilic monomers; q1
represents the number of repeat units in P1 and has a value between
1 and 50; q2 represents the number of repeat units in P2 and has a
value between 30 and 500; q3 represents the number of repeat units
in P3 and has a value between 30 and 500; r represents the number
of homopolymeric arms covalently attached to the Core; t represents
the number of copolymeric arms covalently attached to the Core; and
wherein the molar ratio of r to t is in the range of between 20:1
and 2:1.
2. The star macromolecule of claim 1, wherein the one or more star
macromolecules have a molecular weight of between 150,000 g/mol and
600,000 g/mol.
3. The star macromolecule of claim 1, wherein the sum total number
of arms (r+t) is between 15 and 45.
4. The star macromolecule of claim 1, wherein the molar ratio of r
to t is in the range of between 8:1 and 3:1.
5. The star macromolecule of claim 1, wherein both q2 and q3 have a
value greater than 100, and wherein q2 is greater than q3.
6. The star macromolecule of claim 1, wherein the arms represented
by [(P1).sub.q1-(P2).sub.q2] have an HLB value greater than 18.
7. The star macromolecule of claim 1, wherein the P1 homopolymeric
segment is a hydrophobic homopolymeric segment having an HLB value
of less than 7.
8. The star macromolecule of claim 1, wherein the core comprises a
hydrophobic crosslinked polymeric segment.
9. The star macromolecule of claim 1, wherein the star
macromolecule is a water soluble mikto star macromolecule.
10. The star macromolecule of claim 1, wherein the star
macromolecule, when dissolved in water at a concentration of at
least 0.2 wt. %, forms a clear, homogeneous gel having a viscosity
of at least 20,000 cP.
11. A star macromolecule having a molecular weight of between
150,000 g/mol and 600,000 g/mol that forms a clear, homogeneous gel
when dissolved in water at a concentration of at least 0.2 wt. %;
wherein the gel has: i) a dynamic viscosity of at least 20,000 cP;
ii) a salt-induced break value of at least 60%; iii) a
shear-thinning value of at least 10; and/or iv) an emulsion value
of greater than 12 hours.
12. The star macromolecule of claim 11, wherein the gel-forming
star macromolecule has a viscosity of greater than 40,000 cP at a
pH between 6 to 11.
13. The star macromolecule of claim 11, wherein the gel-forming
star macromolecule has a viscosity of less than 5,000 cP at a shear
rate of 4 sec.sup.-1.
14. The star macromolecule of claim 11, wherein the gel-forming
star macromolecule has a PDI of less than 2.5.
15. The star macromolecule of claim 11, wherein the gel-forming
star macromolecule is a water-soluble mikto star macromolecule.
16. The star macromolecule of claim 11, wherein the gel-forming
star macromolecule has between 15 to 45 arms.
17. The star macromolecule of claim 11, wherein the arms of the
gel-forming star macromolecule comprise hydrophilic homopolymeric
arms and copolymeric arms, comprising hydrophilic polymeric
segments and hydrophobic polymeric segments.
18. The star macromolecule of claim 17, wherein the arms of the
gel-forming star macromolecule have an HLB of between 18 and
20.
19. An emulsion comprising: a water-soluble star macromolecule
having: i) a molecular weight of at least 150,000 g/mol; and ii) a
dynamic viscosity of at least 20,000 cP at a concentration of 0.4
wt. %.
20. The emulsion of claim 19, wherein the emulsion is an
emulsifier-free emulsion.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from U.S.
application Ser. No. 12/926,143, filed Oct. 27, 2010, which is
further a continuation-in-part of U.S. application Ser. No.
12/799,411, filed Apr. 23, 2010, which itself claims further
priority from U.S. Provisional Application No. 61/214,397, filed
Apr. 23, 2009. All of the foregoing related applications, in their
entirety, are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to multi-arm star
macromolecules which are used as rheology modifiers, including use
in the cosmetic, personal care and home care compositions.
BACKGROUND AND PRIOR ART
[0003] Most personal care products on the market contain many types
of polymers that vary by structure, chemistry, and raw material
source (synthetic or natural) that are combined to provide products
with many different desired functions. One class of polymer
additives is targeted at altering or modifying the rheological
properties of the product that are very important for consumer
appeal. Often, additives that provide sufficient viscosity are
needed, especially for those formulations where the viscosity
without additives is close to that of the pure solvent (water).
However, merely increasing viscosity is not sufficient, and in
reality, the modifiers should be selected to provide certain
desired rheological properties for the formulation that depend on
its nature, the mode of delivery, type of flow, and the aesthetic
appeal of final application. Typically, low molecular weight
surfactants are used to modify rheological properties but they have
to be used at large concentrations. Resulting in relatively high
cost, and an adverse impact on the environment (e.g., water
pollution).
[0004] The thickeners used in cosmetic and body care preparations
have to meet stringent requirements. First and foremost, they have
to show high compatibility and also--if possible--biodegradability
so that many substances have to be ruled out from the outset for
use in cosmetics. In addition, they should be universally useable
in aqueous, emulsoidal, alcoholic and oil-containing bases, be
readily processable and lead to a rheology which enables the
product to be easily applied so that the preparations can be
removed and distributed under clean and simple conditions.
[0005] Thickeners that are designed molecular level to provide the
desired properties would be expected to be compatible with many
other auxiliaries, more particularly with salts and surfactants.
The thickener itself and the other auxiliaries should also lend
themselves to ready incorporation into the formulation. The
thickened preparations are also expected to show stable rheology
and an unchanging physical and chemical quality even in the event
of long-term storage and changes in pH and temperature. Finally,
the thickeners should be inexpensive to produce without causing
significant environmental pollution.
[0006] In view of this complex requirement profile, it is clear
why, even today, there is still a demand for new thickeners in the
cosmetics field.
SUMMARY OF THE INVENTION
[0007] Accordingly, in one aspect the invention provides a polymer
composition comprising star macromolecules, each star macromolecule
having a core and five or more arms, wherein the number of arms
within a star macromolecule varies across the composition of star
molecules; and the arms on a star are covalently attached to the
core of the star; each arm comprises one or more (co)polymer
segments; and at least one arm and/or at least one segment exhibits
a different solubility from at least one other arm or one other
segment, respectively, in a reference liquid of interest.
[0008] The use of the polymer composition in personal care products
and home care products is also provided.
[0009] In one aspect of the invention, there is a process of
forming a mikto star macromolecule comprising:
i) creating a reaction mixture comprising a plurality of first
polymeric segments having an ATRP-functional terminal group and a
plurality of second monomers, wherein at least a portion of the
first polymeric segments are formed by polymerizing a plurality of
first monomers, non-limiting examples of first monomers include
hydrophobic monomers; ii) forming a second polymeric segment
extending from said first polymeric segment by activating the
ATRP-functional terminal group on said first polymeric segment to
initiate polymerization of a portion of the second monomers, to
form a plurality of block copolymeric arms; iii) during the
polymerization of the second monomers, introducing a plurality of
second monomer initiators having an ATRP functional terminal group
into the reaction mixture; iv) activating the ATRP-functional
terminal group on said second monomer initiator to initiate
polymerization of a second portion of the second monomer, to form a
plurality of homopolymeric arms; and v) crosslinking at least a
portion of the block copolymeric arms and at least a portion of the
homopolymeric arms to form at least one mikto star
macromolecule.
[0010] In one aspect of the invention, there is a star
macromolecule that forms a gel when dissolved in water at a
concentration of at least 0.2 wt. % and is formed by:
i) creating a reaction mixture comprising a plurality of first
polymeric segments having an ATRP-functional terminal group and a
plurality of second monomers, wherein at least a portion of the
first polymeric segments are formed by polymerizing a plurality of
first monomers; ii) forming a second polymeric segment extending
from said first polymeric segment by activating the ATRP-functional
terminal group on said first polymeric segment to initiate
polymerization of a portion of the second monomers, to form a
plurality of block copolymeric arms; iii) during the polymerization
of the second monomers, introducing a plurality of second monomer
initiators having an ATRP functional terminal group into the
reaction mixture; iv) activating the ATRP-functional terminal group
on said second monomer initiator to initiate polymerization of a
second portion of the second monomer, to form a plurality of
homopolymeric arms; and v) crosslinking at least a portion of the
block copolymeric arms and at least a portion of the homopolymeric
arms; wherein: a) the gel has a dynamic viscosity of at least
20,000 cP; and b) the star macromolecule has a molecular weight of
150,000 g/mol and 600,000 g/mol.
[0011] In one aspect of the invention, there is a star
macromolecule polymer composition comprising one or more star
macromolecules prepared by an improved, efficient arm-first
living-controlled radical polymerization method, wherein the one or
more star macromolecules are represented by Formula X:
[(P1).sub.q1-(P2).sub.q2].sub.t-Core-[P3).sub.q3].sub.r Formula
X
wherein: Core represents a crosslinked polymeric segment; P1
represents a hydrophobic homopolymeric segment comprised of repeat
units of monomeric residues of polymerized hydrophobic monomers; P2
represents a hydrophilic homopolymeric segment comprised of repeat
units of monomeric residues of polymerized hydrophilic monomers; P3
represents a hydrophilic homopolymeric segment comprised of repeat
units of monomeric residues of polymerized hydrophilic monomers; q1
represents the number of repeat units in P1 and has a value between
1 and 50; q2 represents the number of repeat units in P2 and has a
value between 30 and 500; q3 represents the number of repeat units
in P3 and has a value between 30 and 500; r represents the number
of homopolymeric arms covalently attached to the Core; t represents
the number of copolymeric arms covalently attached to the Core; and
wherein the molar ratio of r to t is in the range of between 20:1
and 2:1.
[0012] In one aspect of the invention, there is a star
macromolecule having a molecular weight of between 150,000 g/mol
and 600,000 g/mol that forms a clear homogeneous gel when dissolved
in water at a concentration of at least 0.2 wt. % wherein the gel
has:
i) a dynamic viscosity of at least 20,000 cP; ii) a salt-induced
break value of at least 60%; iii) a pH-induced break value of at
least 80%; iv) a shear-thinning value of at least 10; and/or v) an
emulsion value of >12 hours.
[0013] In one aspect of the invention, there is a clear homogeneous
gel, comprising a star macromolecule having a molecular weight of
between 150,000 g/mol and 600,000 g/mol, comprises the following
properties:
i) a dynamic viscosity of at least 20,000 cP; ii) a salt-induced
break value of at least 60%; iii) a pH-induced break value of at
least 80%; iv) a shear-thinning value of at least 10; and/or v) an
emulsion value of >12 hours; wherein the clear homogeneous gel
is formed when the star macromolecule is dissolved in water at a
concentration of at least 0.2 wt. %.
[0014] In one aspect of the invention, there is an emulsifier-free
emulsion comprising: a water-soluble star macromolecule having:
i) molecular weight of at least 150,000 g/mol; and ii) a dynamic
viscosity of at least 20,000 cP at a concentration of 0.4 wt.
%.
[0015] In one aspect of the invention, there is an emulsion
comprising: a water-soluble star macromolecule having:
i) a molecular weight of at least 150,000 g/mol; and ii) a dynamic
viscosity of at least 20,000 cP at a concentration of 0.4 wt.
%.
[0016] In one aspect of the invention, there is a thickening agent
that forms a clear homogeneous gel when dissolved in water at a
concentration of at least 0.2 wt. %, wherein the gel has:
i) a dynamic viscosity of at least 20,000 cP; ii) a salt-induced
break value of at least 60%; iii) a pH-induced break value of at
least 80%; iv) a shear-thinning value of at least 10; and/or v) an
emulsion value of greater than 12 hours.
[0017] In one aspect of the invention, the star macromolecule,
emulsfier, gel, emusilfier-free emulsion, emulsion and/or
thickening agent, including those formed by the one-pot process,
ATRP, CRP, and/or combinations of one or more of these processes,
may be used to provide a certain level of control over viscosity
and consistency factors in many aqueous and oil based systems
including, for example, water- and solvent-based coating
compositions, paints, inks, antifoaming agents, antifreeze
substances, corrosion inhibitors, detergents, oil-well
drilling-fluid rheology modifiers, additives to improve water
flooding during enhanced oil recovery, dental impression materials,
cosmetic and personal care applications including hair styling,
hair sprays, mousses, hair gels, hair conditioners, shampoos, bath
preparations, cosmetic creams, cosmetic gels, lotions, ointments,
deodorants, powders, skin cleansers, skin conditioners, skin
emollients, skin moisturizers, skin wipes, sunscreens, shaving
preparations, and fabric softeners.
[0018] In one aspect of the invention, there is a macromolecule,
comprising: a plurality of arms comprising at least two types of
arms, wherein a first-arm-type extends beyond a second-arm-type and
said first-arm-type has a hydrophobic segment on its distal end,
wherein at least a portion of the hydrophobic segment may extend
beyond the length of the second-arm-types either by the size of the
monomeric segment or segments (which may be varied by length of
monomeric residue, degree of polymerization, and/or both) for which
the hydrophobic segment is attached. Recognizing that the "length"
of an arm or segment and the "extending beyond" limitation may be
theoretical, meaning that while it is not emperically measured it
is understood to "extend beyond" and/or have a longer "length"
relative to the length of the second-arm-type if the degree of
polymerization is greater for monomeric residues of the same type
or of the same theoretical length.
[0019] In one aspect of the invention, there is a star
macromolecule, comprising: a plurality of arms comprising at least
two types of arms, wherein the degree of polymerization of a
first-arm-type is greater than the degree of polymerization of a
second-arm-type, and wherein said first-arm-type has a distal end
portion that is hydrophobic. In another aspect of the invention,
this star macromolecule may be formed by first forming or obtaining
the hydrophobic portion and then forming the remaining portion of
the first-arm-type from the end of the hydrophobic portion and the
second-arm-type in a one-pot synthesis wherein the poylmerization
of the second portion of the first-arm-type is commenced prior to
the initialization of the second-arm-type but there is at least
some point wherein portions, e.g., substantial portions, of the
first-arm-type and second-arm-type are being polymerically extended
simultaneously.
[0020] In one aspect of the invention, there is an oil-soluble star
macromolecule, comprising: a plurality of different arms comprising
at least two types of arms, wherein a first-arm-type extends beyond
a second-arm-type and said first-arm-type has a hydrophilic segment
on its distal end.
[0021] In one aspect of the invention, there is an oil-soluble star
macromolecule, comprising: a plurality of arms comprising at least
two types of arms, wherein the degree of polymerization of a
first-arm-type is greater than the degree of polymerization of a
second-arm-type, and wherein said first-arm-type has a hydrophilic
segment on its distal end.
[0022] In one aspect of the invention, there is a star
macromolecule, comprising: a plurality of arms comprising at least
two types of arms, wherein the degree of polymerization of a
first-arm-type is greater than the degree of polymerization of a
second-arm-type, and wherein said first-arm-type has a distal end
portion that is hydrophobic and the proximal portion of the
first-arm-type and second-arm-type are the same with the only
difference between the first-arm-type and the second-arm-type being
that the first-arm-type has a hydrophobic portion on its distal
end. In another aspect of the invention, this star macromolecule
may be formed by first forming or obtaining the hydrophobic portion
and then forming the remaining portion of the first-arm-type from
the end of the hydrophobic portion and the second-arm-type
simultaneously in a one-pot synthesis.
[0023] In an aspect of the invention, the star macromolecules may
have an HLM of greater than 0.85, for example greater than 0.87. or
0.9 or 0.93 or 0.95 or 0.97 or 0.98.
[0024] In an aspect of the invention, the star macromolecules may
have a calculated HLM of greater than 0.85, for example greater
than 0.87. or 0.9 or 0.93 or 0.95 or 0.97 or 0.98 and a viscosity
of greater than 60,000 cP at a pH between 7 to 10.5 and a molecular
weight of between 200,000 g/mol and 550,000 g/mol and a
shear-thinning value of at least 10 and, optionally, a salt-induced
break value of at least 60%.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The features and advantages of the present invention may be
better understood by reference to the accompanying Figures, in
which:
[0026] FIG. 1: Illustration of the structure of a segmented
homo-arm star macromolecule and two different types of mikto-arm
star macromolecules.
[0027] FIG. 2: GPC curve for the polystyrene macroinitiator formed
in step 1 of the synthesis of an exemplary (PSt-b-PAA) star
macromolecule.
[0028] FIG. 3: GPC curves for the polystyrene macroinitiator formed
in step 1 of the synthesis of an exemplary (PSt-b-PAA) star
macromolecule and GPC curve for block copolymer formed after chain
extension with tBA in step 2 of the synthesis.
[0029] FIG. 4: GPC curves of the PSt-b-tBA block copolymer and the
star macromolecule formed after core formation reaction is step 3
of the formation of an exemplary (PSt-b-PAA) star
macromolecule.
[0030] FIG. 5: Image showing the thickening properties of
(PSt-b-PAA) star macromolecule.
[0031] FIG. 6: Viscosity of aqueous solution of (PSt-b-PAA) star
macromolecule vs. shear rate.
[0032] FIG. 7: Viscosity of aqueous solution of (PSt-b-PAA) star
macromolecule vs. concentration.
[0033] FIG. 8: Viscosity of an aqueous solution and a water/windex
(1/1 v/v) solution of (PSt-b-PAA) star macromolecule vs. shear
rate.
[0034] FIG. 9: Viscosity of an aqueous solution and a water/windex
(1/1 v/v) solution of Carbopol EDT 2020 vs. shear rate.
[0035] FIG. 10: GPC Curves for preparation of the precursor to a
PAA star. Solid line PtBA M.sub.n=18,900 PDI=1.14; Dashed line
(PtBA).sub.X star with M.sub.n,app 112,600 PDI=1.36
[0036] FIG. 11: Viscosity of aqueous solution of (PSt-b-PAA) star
macromolecule and (PAA) star macromolecule vs. shear rate.
[0037] FIG. 12: Images demonstrating the emulsifying properties of
(PSt-b-PAA) star macromolecule.
[0038] FIG. 13: Synthesis of [(PSt-b-PtBA)/(PtBA)] star
macromolecule using arm-first method.
[0039] FIG. 14: GPC curves for C.sub.18-PtBA arm star
macromolecule, Solid line C.sub.18-PtBA arm with M.sub.n=19,200
PDI=1.16; dashed line (C.sub.18-PtBA).sub.X star macromolecule
M.sub.n,app=95,600 PDI=1.48.
[0040] FIG. 15. GPC curves for C.sub.12-PtBA arm star
macromolecule, Solid Line C.sub.12-PtBA M.sub.n=17,500 PDI=1.22;
Dashed line (C.sub.12-PtBA).sub.X M.sub.n,app 113,900 PDI=1.53.
[0041] FIG. 16: is a graph comparing viscosity of Advantomer and
Carbopol ETD 2020 at varying thickening agent weight %.
[0042] FIG. 17: is a graph comparing viscosity of Advantomer and
Carbopol ETD 2020 at varying shear rates.
[0043] FIG. 18: is a graph comparing viscosity of Advantomer and
Carbopol ETD 2020 at varying NaCl weight %.
[0044] FIG. 19: is a graph comparing viscosity of Advantomer and
Carbopol ETD 2020 at varying pH.
[0045] FIG. 20: is a graph comparing viscosity of Advantomer and
Carbopol ETD 2020 at varying H.sub.2O.sub.2 weight %.
[0046] FIG. 21: is a graph comparing viscosity of Advantomer and
Carbopol ETD 2020 at varying temperatures.
[0047] FIG. 22: is a graph comparing viscosity of Advantomer and
Carbopol ETD 2020 at varying NaCl weight %.
[0048] FIG. 23: GPC curves for the reaction product resulting from
step 2 of Example 9.
[0049] FIG. 24: GPC curves for the reaction product resulting from
step 3 of example 9.
DETAILED DESCRIPTION OF THE INVENTION
[0050] The term "solubility" or "soluble" is understood to mean
that when a component is mixed into a solvent and tested, at STP in
a 1 cm cuvette, it has a light transmittance value, at a wavelength
at or around a UV/Vis minimum wavelength for the mixture, of at
least 40%, for example, at least 50%, 70%, 85%, or at least
95%.
[0051] The term "clear" as is used to describe a homogenous gel or
homogenous solution is understood to mean that when the gel or
solution is tested, at STP in a 1 cm cuvette, it has a light
transmittance value, at a wavelength at or around a UV/Vis minimum
wavelength for the gel or solution, of at least 40%, for example,
at least 50%, 70%, 85%, or at least 95%.
[0052] The term "water-soluble monomer" is understood to mean a
monomer having at least about 10 wt. % solubility in water at STP.
For example, a water soluble monomer may have at least 15 wt. %, 20
wt. %, 25 wt. %, or at least 30 wt. % solubility in water at
STP.
[0053] The term "water-insoluble monomer" is understood to mean a
monomer having less water solubility than a water soluble monomer,
for example, less that about 5 wt. %, such as less than 1 wt. % or
0.5 wt. % solubility in water at STP.
[0054] The term "water-soluble star macromolecule" is understood to
mean a star macromolecule that is soluble in water, pH adjusted if
necessary to a pH of no greater than 8 with sodium hydroxide, at a
concentration of at least 5 g/L, for example, between 8 g/L to 100
g/L, such as, at least 10 g/L, 12 g/L, 15 g/L, or at least 20 g/L.
For example, a water-soluble star macromolecule having an aqueous
solubility of at least 10 g/L may include the introduction of at
least 10 g of the star macromolecule into approximately 1 L of
water, neutralizing the mixture, if necessary, by adjusting the pH
of the resulting mixture to about pH 8 (e.g., with the addition of
base, such as sodium hydroxide), and vigorously stirring at a
temperature no greater than 100.degree. C. for no more than about
60 minutes, to achieve dissolution of the star macromolecule, and
testing the solubility at STP.
[0055] The term "oil-soluble star macromolecule" is understood to
mean a star macromolecule that is soluble in mineral oil at a
concentration of at least 5 g/L, for example, between 8 g/L to 100
g/L, such as, at least 10 g/L, 12 g/L, 15 g/L, or at least 20 g/L
of mineral oil. For example, an oil-soluble star macromolecule
having an oil solubility of at least 10 g/L may include the
introduction of at least 10 g of the star macromolecule into
approximately 1 L of mineral oil, and vigorously stirring at a
temperature no greater than 100.degree. C. for no more than about
60 minutes, to achieve dissolution of the star macromolecule, and
testing the solubility at STP.
[0056] The term "hydrophilic" is understood to mean, in relation to
a material, such as a polymeric arm, or a polymeric segment of a
polymeric arm, that the material is water soluble and comprises
hydrophilic segments having an HLB equal to or greater than 8, for
example, an HLB equal to 16-20, or equal to or greater than 18, 19,
or 19.5. In certain embodiments, the hydrophilic segment may
comprise at least 75 mol % of water-soluble monomer residues, for
example, between 80 mol % to 100 mol % or at least 85 mol %, 90 mol
%, 95 mol %, or at least 97 mol % water-soluble monomer
residues.
[0057] The term "hydrophobic" is understood to mean, in relation to
a material, such as a polymeric arm, or a polymeric segment of a
polymeric arm, that the material is water insoluble and comprises
hydrophobic segments having an HLB less than 8, for example, an HLB
less than 7. In certain embodiments, the hydrophobic segment may
comprise at least 75 mol % of water-insoluble monomer residues, for
example, between 80 mol % to 100 mol % or at least 85 mol %, 90 mol
%, 95 mol %, or at least 97 mol % water-insoluble monomer
residues.
[0058] The term "monomer residue" or "monomeric residue" is
understood to mean the residue resulting from the polymerization of
the corresponding monomer. For example, a polymer derived from the
polymerization of an acrylic acid monomer (or derivatives thereof,
such as acid protected derivatives of acrylic acid including but
not limited to methyl or t-butyl ester of acrylic acid), will
provide polymeric segments, identified as PAA, comprising repeat
units of monomeric residues of acrylic acid, i.e. ,
"--CH(CO.sub.2H)CH.sub.2-". For example, a polymer derived from the
polymerization of styrene monomers will provide polymeric segments,
identified as PS, comprising repeat units of monomeric residues of
styrene, i.e., "--CH(C.sub.6H.sub.5)CH.sub.2--." For example, a
polymer derived from the polymerization of monomeric divinylbenzene
monomers will provide polymeric segments comprising repeat units of
monomeric residues of divinylbenzene, i.e.,
"--CH.sub.2CH(C.sub.6H.sub.5)CHCH.sub.2--."
[0059] The term "emulsifier" is understood to mean a component that
comprises an appreciable weight percent of an amphiphilic compound
having a molecular weight of less than 5,000 MW. Emulsifiers are
usually linear organic compounds that contain both hydrophobic
portions (tails) and hydrophilic portions (heads), i.e., are
amphiphilc. Examples of emulsifiers include but are not limited to:
alkyl benzenesulfonates, alkanesulfonates, olefin sulfonates,
alkylethersulfonates, glycerol ether sulfonates, .alpha.-methyl
ester sulfonates, sulfofatty acids, alkyl sulfates, fatty alcohol
ether sulfates, glycerol ether sulfates, hydroxy mixed ether
sulfates, monoglyceride (ether) sulfates, fatty acid amide (ether)
sulfates, mono- and dialkylsulfosuccinates, mono- and
dialkylsulfosuccinamates, sulfotriglycerides, ether carboxylic
acids and salts thereof, fatty acid isethionates, fatty acid
sarcosinates, fatty acid taurides, acyl lactylates, acyl tartrates,
acyl glutamates, acyl aspartates, alkyl oligoglucoside sulfates,
protein fatty acid condensates (particularly wheat-based vegetable
products) and alkyl (ether) phosphates, alkylbetaines,
alkylamidobetaines, aminopropionates, aminoglycinates,
imidazoliniumbetaines and sulfobetaines.
[0060] The term "emulsifier-free" is understood to mean a
composition or mixture wherein the formulation is substantially
deviod of any emulsifiers, for example less than 0.1 wt. % of
emulsifier, relative to the total composition, or less than 0.05
wt. % of emulsifier, relative to the total composition, or less
than 0.01 wt. % of emulsifier, relative to the total composition,
or a formulation where there is no emulsifier.
[0061] The term "STP" is understood to mean standard conditions for
temperature and pressure for experimental measurements, wherein the
standard temperature is a temperature of 25.degree. C. and the
standard pressure is a pressure of 1 atm.
Structure of the Polymer Composition
[0062] Multi-arm star macromolecules are shown schematically in
FIG. 1
[0063] In one embodiment, the arms in a star macromolecule are
comprised of two or more (co)polymer segments selected to modify
the rheology of the reference liquid of interest. The star
macromolecule structure is represented by the following formula
[F-(M1).sub.p1-(M2).sub.p2].sub.n-C wherein [0064] i.
[F-(M1).sub.p1-(M2).sub.p2] represents an arm comprised of a
segmented (co)polymer chain wherein each (co)polymer segment,
[0065] ii. (M1).sub.p1- and (M2).sub.p2- are compositionally
distinct adjacent (co)polymer segments where each segment is
comprised of one or more monomers with homo, random, gradient or
block (co)polymer structure and where p1 and p2 represent the
degree of polymerization of each copolymer segment, [0066] iii. F-
represents an optionally functional group or mixture of functional
groups present on the arm chain-end, [0067] iv. (M1).sub.p1 is not
soluble or not fully soluble in the reference liquid of interest,
[0068] v. (M2).sub.p2 is soluble or mostly soluble in the reference
liquid of interest, [0069] vi. and C represents the crosslinked
core of the star macromolecule which is comprised of crosslinker
(Mx), crosslinker (Mx) and monomer (My), crosslinker (Mx) and (M2),
or a mixture of (Mx), (My) and (M2), and [0070] vii. n represents
the average number of arms covalently attached to the core of the
star macromolecule.
[0071] In another embodiment, the star macromolecule structure can
be represented by the following formula,
[F-(M1).sub.p1-(M2).sub.p2].sub.n-C-[(M3).sub.p3-].sub.m wherein
[0072] i. [F-(M1).sub.p1-(M2).sub.p2] represents an arm comprised
of a segmented (co)polymer chain, [0073] ii. (M1).sub.p1- and
(M2).sub.p2- are compositionally distinct adjacent (co)polymer
segments where each segment is comprised of one or more monomers
with homo, random, gradient or block (co)polymer structure and
where p1 and p2 represent the degree of polymerization of each
copolymer segment, [0074] iii. F- represents an optionally
functional group or mixture of functional groups present on the arm
chain-end, [0075] iv. (M1).sub.p1 is not soluble or not fully
soluble in the reference liquid of interest, [0076] v. (M2).sub.p2
is soluble or mostly soluble in the reference liquid of interest,
[0077] vi. and C represents the crosslinked core of the star
macromolecule which is comprised of crosslinker (Mx), crosslinker
(Mx) and monomer (My), crosslinker (Mx) and (M2), or a mixture of
(Mx), (My) and (M2), and [0078] vii. n represents the average
number of arms covalently attached to the core of the star
macromolecule. [0079] viii. (M3).sub.p3 is a (co)polymer segment
which is comprised of one or more monomers with homo, random,
gradient or block (co)polymer structure with a degree of
polymerization p3 and [0080] ix. m is the number of (M3).sub.p3
(co)polymer arms covalently attached to the core, [0081] x.
(M3).sub.p3 is soluble or mostly soluble in the reference liquid of
interest and [0082] xi. M2 and M3 can be comprised of the same or
different (co)monomers.
[0083] In a further embodiment, polymer composition comprises star
macromolecules in which the structure of a star can be represented
by the following formula,
[F-(M1).sub.p1].sub.s-C-[(M3).sub.p3-F].sub.m wherein [0084] i.
[F-(M1).sub.p1-(M2).sub.p2] represents an arm comprised of a
segmented (co)polymer chain, [0085] ii. (M1).sub.p1- is a
(co)polymer segment where each segment is comprised of one or more
monomers with homo, random, gradient or block (co)polymer structure
with a degree of polymerization p1, [0086] iii. F- represents an
optionally functional group or mixture of functional groups present
on the arm chain-end, [0087] iv. (M1).sub.p1 is not soluble or not
fully soluble in the reference liquid of interest, [0088] v. C
represents the crosslinked core of the star macromolecule which is
comprised of crosslinker (Mx), crosslinker (Mx) and monomer (My),
crosslinker (Mx) and (M2), or a mixture of (Mx), (My) and (M2), and
[0089] vi. (M3).sub.p3 is a (co)polymer segment which is comprised
of one or more monomers with homo, random, gradient or block
(co)polymer structure with a degree of polymerization p3 and [0090]
vii. (M3).sub.p3 is soluble or mostly soluble in the reference
liquid of interest and [0091] viii. m is the number of (M3).sub.p3
(co)polymer arms covalently attached to the core, and [0092] ix. s
is the average number of (M1).sub.p1 (co)polymer arms covalently
attached to the core.
[0093] In an embodiment, the polymer composition, the number of
arms on any particular star varies across the population of star
macromolecules in each composition, due to the synthetic process
used for the synthesis of the composition. This process is called
"arm first" method and is described in details herein below. Due to
variation in the number of arms in star macromolecules, the number
of arms n, m and s are referred as an average number of arms.
[0094] Star macromolecules with a single peak in the GPC curve with
a polydispersity index (PDI) above 1.0 and below 2.5 is
preferred.
[0095] As used herein, the term "reference liquid of interest"
means the liquid to which the polymer composition will be added.
Suitable examples of reference liquids include, but are not limited
to, water, oil or mixture thereof or water with additives which
include but are not limited to; surfactants, oils, fats and waxes,
emulsifiers, silicone compounds, UV protectors, antioxidants,
various water soluble substances, biogenic agents, deodorants, odor
absorbers, antiperspirants, and germ and enzyme inhibitors. Such
agents are disclosed in U.S. Pat. Nos. 6,663,855 and U.S. 7,318,929
and are herein incorporated by reference to provide definitions for
those terms.
[0096] Arms of a star can possess the same composition or be
different (e.g. star macromolecule with formula (1) vs. (2) or (3),
these star are shown in FIG. 1). The difference can be in
composition or molecular weight or both (e.g. different monomer
units M1, M2, M3 and/or different degree of polymerization p1, p2,
p3).
[0097] Term "(co)polymer" is defined as a polymer derived from two
(or more) monomeric species (monomer units)
[0098] More preferred specific monomer units as a building blocks
of M1, M2, M3 and My include those selected from protected and
unprotected acrylic acid, methacrylic acid, ethacrylic acid, methyl
acrylate, ethyl acrylate, .alpha.-butyl acrylate, iso-butyl
acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate,
octyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl
methacrylate, iso-butyl methacrylate, t-butyl methacrylate,
2-ethylhexyl methacrylate, decyl methacrylate, methyl ethacrylate,
ethyl ethacrylate, n-butyl ethacrylate, iso-butyl ethacrylate,
t-butyl ethacrylate, 2-ethylhexyl ethacrylate, decyl ethacrylate,
2,3-dihydroxypropyl acrylate, 2,3-dihydroxypropyl methacrylate,
2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, hydroxypropyl
methacrylate, glyceryl monoacrylate, glyceryl monoethacrylate,
glycidyl methacrylate, glycidyl acrylate, acrylamide,
methacrylamide, ethacrylamide, N-methyl acrylamide, N,N-dimethyl
acrylamide, N,N-dimethyl methacrylamide, N-ethyl acrylamide,
N-isopropyl acrylamide, N-butyl acrylamide, N-t-butyl acrylamide,
N,N-di-n-butyl acrylamide, N,N-diethylacrylamide, N-octyl
acrylamide, N-octadecyl acrylamide, N,N-diethylacrylamide, N-phenyl
acrylamide, N-methyl methacrylamide, N-ethyl methacrylamide,
N-dodecyl methacrylamide, N,N-dimethylaminoethyl acrylamide,
quaternised N,N-dimethylaminoethyl acrylamide,
N,N-dimethylaminoethyl methacrylamide, quaternised
N,N-dimethylaminoethyl methacrylamide, N,N-dimethylaminoethyl
acrylate, N,N-dimethylaminoethyl methacrylate, quaternised
N,N-dimethyl-aminoethyl acrylate, quaternised
N,N-dimethylaminoethyl methacrylate, 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate, 2-hydroxyethyl ethacrylate, glyceryl
acrylate, 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate,
2-methoxyethyl ethacrylate, 2-ethoxyethyl acrylate, 2-ethoxyethyl
methacrylate, 2-ethoxyethyl ethacrylate, maleic acid, maleic
anhydride and its half esters, fumaric acid, itaconic acid,
itaconic anhydride and its half esters, crotonic acid, angelic
acid, diallyldimethyl ammonium chloride, vinyl pyrrolidone vinyl
imidazole, methyl vinyl ether, methyl vinyl ketone, maleimide,
vinyl pyridine, vinyl pyridine-N-oxide, vinyl furan, styrene
sulphonic acid and its salts, allyl alcohol, allyl citrate, allyl
tartrate, vinyl acetate, vinyl alcohol, vinyl caprolactam, vinyl
acetamide, vinyl formamide and mixtures thereof.
[0099] Even more preferred monomer units as a building parts of M1,
M2, M3 and My are those selected from methyl acrylate, methyl
methacrylate, methyl ethacrylate, ethyl acrylate, ethyl
methacrylate, ethyl ethacrylate, n-butyl acrylate, n-butyl
methacrylate, n-butyl ethacrylate, 2-ethylhexyl acrylate,
2-ethylhexyl methacrylate, 2-ethylhexyl ethacrylate, N-octyl
acrylamide, 2-methoxyethyl acrylate, 2-hydroxyethyl acrylate,
N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl
methacrylate, acrylic acid, methacrylic acid, N-t-butylacrylamide,
N-sec-butylacrylamide, N,N-dimethylacrylamide,
N,N-dibutylacrylamide, N,N-dihydroxyethyllacrylamide 2-hydroxyethyl
acrylate, 2-hydroxyethyl methacrylate, benzyl acrylate,
4-butoxycarbonylphenyl acrylate, butyl acrylate, 4-cyanobutyl
acrylate, cyclohexyl acrylate, dodecyl acrylate, 2-ethylhexyl
acrylate, heptyl acrylate, iso-butyl acrylate, 3-methoxybutyl
acrylate, 3-methoxypropyl acrylate, methyl acrylate, N-butyl
acrylamide, N,N-dibutyl acrylamide, ethyl acrylate, methoxyethyl
acrylate, hydroxyethyl acrylate, diethyleneglycolethyl acrylate,
styrene (optionally substituted with one or more C.sub.1-C.sub.12
straight or branched chain alkyl groups), alpha-methylstyrene,
t-butylstyrene, p-methylstyrene, and mixtures thereof.
[0100] Monomer units within the arms may be connected with C--C
covalent bonds. This is believed to make them hard to degrade so
that the star macromolecule may perform as efficient thickening
agent in a harsh environment (very high/low pH or in the presence
of strong oxidizing agents).
[0101] When "C" represents the crosslinked core of the star
macromolecule it may be comprised of crosslinker (Mx), crosslinker
(Mx) and monomer (My), crosslinker (Mx) and (M2), or a mixture of
(Mx), (My) and (M2).
[0102] Suitable crosslinkers (Mx) encompass all of the compounds
which are capable, under the polymerization conditions, of bringing
about crosslinking These include but are not limited di-, tri-,
tetra-functional (meth)acrylates, di-, tri- and tetra-functional
styrenes and other multi- or poly-functional crosslinkers.
[0103] Some examples of the crosslinking agents may include but are
not limited to 1,2-divinylbenzene, 1,3-divinylbenzene and
1,4-divinylbenzene, 1,2-ethanediol di(meth)acrylate,
1,3-propanediol di(meth)acrylate, 1,4butanediol di(meth)acrylate,
1,5-hexanediol di(meth)acrylate, divinylbenzene, ethyleneglycol
di(meth)acrylate, propyleneglycol di(meth)acrylate, butyleneglycol
di(meth)acrylate, triethyleneglycol di(meth)acrylate,
polyethyleneglycol di(meth)acrylate, polypropyleneglycol
di(meth)acrylate, polybutyleneglycol di(meth)acrylate, and
allyl(meth)acrylate, glycerol di(meth)acrylate, trimethylolpropane
tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, allyl
methacrylate, allyl acrylate.
[0104] The terms `mostly soluble`, `not fully soluble`, and `not
soluble` are used to describe the extent which a composition which
is capable of being dissolved in a reference liquid of
interest.
[0105] The term `mostly soluble` is used to describe a composition
which is capable dissolves completely with exception of a slight
cloudiness in the reference liquid of interest. The term `not fully
soluble` is used to describe a composition which disperses with a
cloudiness in the reference liquid of interest. The term `not
soluble` is used to describe a composition which does not disperse
and remains as a solid in the reference liquid of interest. A list
of solvents and non-solvent for polymers can be found in "Polymer
Handbook, 4.sup.th Ed." edited by Brandrup J.; Immergut, Edmund H.;
Grulke, Eric A.; Abe, Akihiro; Bloch, Daniel R., John Wiley &
Sons: 2005.
[0106] Multi-arm stars macromolecules are the preferred topology
for an embodiment of the present invention as they can adopt a
globular shape wherein the inner segment, (M2).sub.p2 of each arm
covalently attached to the core, can chain extend in a selected
solvent to attain a highly swollen stable structure. The dispersant
medium can be water, oil or mixture thereof. The degree of
polymerization p2 of the segment (M2), should be higher than that
of p1 of segment (M1) to attain a highly swollen stable structure.
A star macromolecule with p2>(3.times.p1) is more preferred.
[0107] In one embodiment, a star macromolecule described with
formula (2) and shown in FIG. 1B, comprising a fraction of
segmented (co)polymer arms [F-(M1).sub.p1-(M2).sub.p2], the average
number of arms, n, should be greater than two per star,
preferentially greater than three, and can comprise a mole fraction
between 0.5 and 100% of the arms in the average star macromolecule.
The ratio of n to m is more preferably between 100 and 0.1.
[0108] In one embodiment, in a star macromolecule described with
formula (3) and shown in FIG. 1C comprising a fraction of arms
[F-(M1).sub.p1] the average number of arms, o, should be greater
than two per star, preferentially greater than three, and can
comprise a mole fraction between 0.5 and 100% of the arms in the
average star macromolecule. The ratio of o to m is more preferably
between 100 and 0.1.
[0109] An embodiment of the present invention can be exemplified by
a multi-arm star macromolecule wherein the average number of arms
in the star macromolecule is between 5 and 500, preferentially
between 10 and 250.
[0110] In one embodiment, the star macromolecule has a core which
contains additional functionality and/or expanded free volume.
`Expended free volume` of the core is defined as the core with
lower crosslink density. The free volume in the core is generated
when during the crosslinking process crosslinker Mx with monomer M2
or My is used. If M2 or My are monomers with functional groups,
these groups will be incorporated in the core.
[0111] In one embodiment, the star macromolecule may store and
release in controlled rate the small molecules. `Small molecules`
are fragrances, UV absorbers, vitamins, minerals, dyes, pigments,
solvents, surfactants, metal ions, salts, oils, or drugs. These
small molecules can be stored inside the core of the star
macromolecule and next released. Each small molecule has some
affinity to the core, is soluble in the core environment. Higher
affinity of the small molecule to the core will result in the lower
rate of release from star macromolecule. The affinity may be
increased or decreased through non-covalent forces including
H-bonding, electrostatic, hydrophobic, coordination and metal
chelating interactions.
[0112] In one embodiment, the star macromolecule displays shear
thinning behavior. `Shear thinning` is defined as is an effect
where viscosity decreases with increasing rate of shear stress. The
extent of shear thinning behavior is characterized using a
Brookfield-type viscometer where viscosities are measured under
different shear rates.
[0113] In one embodiment, the star macromolecule comprises a
functional group which exhibits H-bonding, coordination,
hydrophobic, metal chelating and/or electrostatic forces. "F"
represents an optionally functional group or mixture of functional
groups present on the arm chain-end. Functional groups (F)
encompass all of the compounds capable of interacting through
non-covalent forces including H-bonding, electrostatic,
hydrophobic, coordination and metal chelating.
[0114] Some examples of F end groups capable of H-bonding include
but are not limited to modified bases adenine, thymine, guanine,
cytosine, or derivatives thereof, peptides etc. Some examples of
endgroups capable of electrostatic interactions include but are not
limited to carboxylate, phosphate, sulfonate, secondary-, tertiary-
and quaternary-amines. Some examples of endgroups capable of
hydrophobic interactions include but are not limited to C1-C30
aliphatic groups, benzyl and aliphatic benzyl groups, saturated and
unsaturated hydrophobes. Some examples of endgroups capable of
coordination interactions include but are not limited to metal ions
and/or metal ion ligands. Some examples of endgroups capable of
metal chelating interactions include derivatives of
diethylenetriamine-N,N,N',N',N''-pentaacetic acid (DTA),
ethylenedinitrilotetraacetic acid (EDTA), or nitrilotriacetic acid
(NTA).
[0115] In one embodiment, the star macromolecule comprises a
functional group F which is designed to interact with small
molecule surfactant micelles. `Interacts with` is defined as any
intermolecular force between two molecules. These intermolecular
forces include electrostatic, hydrogen bonding, hydrophobic,
steric, dipole-dipole, pi-pi, or other intermolecular forces.
[0116] Surfactants represent a class of molecules with a
hydrophobic tail and a hydrophilic head. Some examples of
surfactants include but are not limited to linear
alkylbenzenesulfonate salts (LAS), alkyl ether sulfate salts
(AEOS), alkylpolyglycosides (APG), alcohol ethoxylates, fatty acid
glucoamides, betaines, alpha-olefinsulfonate salts, polysorbates,
PEGs, alkylphenol ethoxylates, esterquats, imidizolium salts,
diamido quaternary ammonium salts, etc.
[0117] In one embodiment, the star macromolecule arms comprise a
(co)polymer segment that exhibits an upper, or higher, critical
solution temperature (UCST or HCST) whereby the star macromolecule
is soluble in a liquid at higher temperature, say above 44.degree.
C., then at the lower use temperature the outer shell polymer
segments become insoluble and self assemble to form a shear
sensitive gel or in another embodiment the invention the outer
shell of the star macromolecule arms comprise a (co)polymer segment
that exhibits a lower critical solution temperature (LCST), say
5.degree. C., whereby the star macromolecule is soluble in a liquid
at lower temperature then at the use temperature the outer shell
polymer segments become insoluble and self assemble to form a shear
sensitive gel. In the case of a LCST it is envisioned that a
copolymer segment with an LCST below 10.degree. C., preferable
below 5.degree. C. would be optimal. A non-limiting example would
be a copolymerization of BuMA and DMAEMA and preparation of
copolymers with designed LCST. A copolymer with 10% BuMA has a LCST
close to 0.degree. C. and one would use less BuMA or a less
hydrophobic monomer such as MMA to increase the LCST to
.about.5.degree. C. Indeed the Tg of the segment of the star can be
selected to allow dissolution of the star in room temperature
aqueous media.
[0118] In one embodiment, a star macromolecule further comprise a
personal care and cosmetics formulation and/or product. Personal
care and cosmetic products include but are not limited to a
shampoo, conditioner, hair lotion, tonic, hair spray, hair mousse,
hair gel, hair dyes, moisturizer, suntan lotion, color cosmetic,
body lotion, hand cream, baby skin-care product, facial cream,
lipstick, mascara, blush, eyeliner, baby shampoo, baby moisturizer,
baby lotion, shower gel, soap, shaving product, deodorant, bath
cream, body wash, serum, cream, solid, gel, lubricant, gelly, balm,
tooth paste, whitening gel, disposable towel, disposable wipe or
ointment.
[0119] In one embodiment a star macromolecule further comprise a
home care formulation and/or product. Home care products include
but are not limited to a surface cleaner, window cleaner, laundry
detergent, toilet cleaner, fabric cleaner, fabric softener, dish
detergent, cleaning stick, stain stick, spray cleaners, sprayable
formulations, lubricant, disposable towel or disposable wipe.
[0120] The polymer chains that comprise the arms are preferably
provided with a molecular mass of greater than or equal to 500
which can range up to 2,000,000. This numbers correspond to p1, p2,
p3 in the range of 5 up to 20,000 preferably in the range of 8 to
2,000.
[0121] In one example, the star macromolecules comprising segmented
copolymers arms are directed at use in aqueous media. The stars
comprise a crosslinked core, and arms comprising of water soluble
copolymer (M2).sub.p2 and a hydrophobic (co)polymer (M1).sub.p1.
Therefore in a in a non-limiting example the stars comprise a
crosslinked core, and arms comprising an water soluble (co)polymer
(e.g. poly(acrylic acid), poly(2-hydroxyethyl acrylate),
poly(N-isopropylacrylamide), poly(ethylene glycol) methacrylate,
quaternized poly(dimethylaminoethyl methacrylate), etc.) and a
hydrophobic (co)polymer (e.g. polystyrene or substituted
polystyrenes, poly(alkyl(meth)acrylate), etc.) or a hydrocarbon
based segment. Suitable hydrocarbon based segments can comprise low
molecular weight .alpha.-olefin. Lower molecular weight
.alpha.-olefins are commercially available and higher molecular
weight species can be prepared by telomerization of ethylene or
ethylene propylene mixtures. [Kaneyoshi, H.; Inoue, Y.;
Matyjaszewski, K. Macromolecules 2005, 38, 5425-5435.]
[0122] In an embodiment, the polymer compositions can self assemble
in solution to provide a certain level of control over viscosity
and consistency factors in many aqueous and oil based systems where
control over the rheology is a concern. Applications include;
water- and solvent-based coating compositions, paints, inks,
antifoaming agents, antifreeze substances, corrosion inhibitors,
detergents, oil-well drilling-fluid rheology modifiers, additives
to improve water flooding during enhanced oil recovery, dental
impression materials, cosmetic and personal care applications
including hair styling, hair conditioners, shampoos, bath
preparations, cosmetic creams, gels, lotions, ointments,
deodorants, powders, skin cleansers, skin conditioners, skin
emollients, skin moisturizers, skin wipes, sunscreens, shaving
preparations, and fabric softeners, with the rheology modifier
providing characteristics of high gel strength, highly shear
thinning characteristics, forms versatile low viscosity soluble
concentrations, and synergistic interactions with added agents to
adjust their rheology profile to optimize properties such as
sedimentation, flow and leveling, sagging, spattering, etc.
[0123] One non-limiting field of applications that can exemplify
the utility of the disclosed star macromolecules is cosmetic and
personal care compositions such as hair styling sprays, mousses,
gels and shampoos, frequently contain resins, gums and adhesive
polymers to provide a variety of benefits, for example,
film-forming ability, thickening, sensory properties and hair
shaping and setting. Polymers designed for rheological control, as
thickening agents, in such compositions generally focus on linear
or graft copolymers which contain various monomers in an
alternating, random or block configuration.
[0124] Suitable hydrophobic monomers that may be used to form an
arm or segment of an arm, such as a polymeric segment of an arm, of
a star macromolecule may include, but is not limited to methyl
acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl acrylate,
t-butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, octyl
acrylate; methyl methacrylate; ethyl methacrylate; n-butyl
methacrylate; iso-butyl methacrylate; t-butyl methacrylate;
2-ethylhexyl methacrylate; decyl methacrylate; methyl ethacrylate;
ethyl ethacrylate; n-butyl ethacrylate; iso-butyl ethacrylate;
t-butyl ethacrylate; 2-ethylhexyl ethacrylate; decyl ethacrylate;
2,3-dihydroxypropyl acrylate; 2,3-dihydroxypropyl methacrylate;
2-hydroxypropyl acrylate; hydroxypropyl methacrylate; glycidyl
methacrylate; glycidyl acrylate, acrylamides, styrene; styrene
optionally substituted with one or more C1-C12 straight or branched
chain alkyl groups; or alkylacrylate. For example, the hydrophobic
monomer may comprise styrene; alpha-methylstyrene; t-butylstyrene;
p-methylstyrene; methyl methacrylate; or t-butyl-acrylate. For
example, the hydrophobic monomer may comprise styrene. In certain
embodiments, the hydrophobic monomer may comprise a protected
functional group.
[0125] Suitable hydrophilic monomers that may be used to form an
arm or segment of an arm, such as a polymeric segment of an arm, of
a star macromolecule may include, but is not limited to, protected
and unprotected acrylic acid, such as methacrylic acid, ethacrylic
acid, methyl acrylate, ethyl acrylate, a-butyl acrylate, iso-butyl
acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate,
octyl acrylate; methyl methacrylate; ethyl methacrylate; n-butyl
methacrylate; iso-butyl methacrylate; t-butyl methacrylate;
2-ethylhexyl methacrylate; decyl methacrylate; methyl ethacrylate;
ethyl ethacrylate; n-butyl ethacrylate; iso-butyl ethacrylate;
t-butyl ethacrylate; 2-ethylhexyl ethacrylate; decyl ethacrylate;
2,3-dihydroxypropyl acrylate; 2,3-dihydroxypropyl methacrylate;
2-hydroxyethyl acrylate; 2-hydroxypropyl acrylate; hydroxypropyl
methacrylate; glyceryl monoacrylate; glyceryl monoethacrylate;
glycidyl methacrylate; glycidyl acrylate; acrylamide;
methacrylamide; ethacrylamide; N-methyl acrylamide; N,N-dimethyl
acrylamide; N,N-dimethyl methacrylamide; N-ethyl acrylamide;
N-isopropyl acrylamide; N-butyl acrylamide; N-t-butyl acrylamide;
N,N-di-n-butyl acrylamide; N,N-diethylacrylamide; N-octyl
acrylamide; N-octadecyl acrylamide; N,N-diethylacrylamide; N-phenyl
acrylamide; N-methyl methacrylamide; N-ethyl methacrylamide;
N-dodecyl methacrylamide; N,N-dimethylaminoethyl acrylamide;
quaternised N,N-dimethylaminoethyl acrylamide;
N,N-dimethylaminoethyl methacrylamide; quaternised
N,N-dimethylaminoethyl methacrylamide; N,N-dimethylaminoethyl
acrylate; N,N-dimethylaminoethyl methacrylate; quaternised
N,N-dimethyl-aminoethyl acrylate; quaternised
N,N-dimethylaminoethyl methacrylate; 2-hydroxyethyl acrylate;
2-hydroxyethyl methacrylate; 2-hydroxyethyl ethacrylate; glyceryl
acrylate; 2-methoxyethyl acrylate; 2-methoxyethyl methacrylate;
2-methoxyethyl ethacrylate; 2-ethoxyethyl acrylate; 2-ethoxyethyl
methacrylate; 2-ethoxyethyl ethacrylate; maleic acid; maleic
anhydride and its half esters; fumaric acid; itaconic acid;
itaconic anhydride and its half esters; crotonic acid; angelic
acid; diallyldimethyl ammonium chloride; vinyl pyrrolidone vinyl
imidazole; methyl vinyl ether; methyl vinyl ketone; maleimide;
vinyl pyridine; vinyl pyridine-N-oxide; vinyl furan; styrene
sulphonic acid and its salts; allyl alcohol; allyl citrate; allyl
tartrate; vinyl acetate; vinyl alcohol; vinyl caprolactam; vinyl
acetamide; or vinyl formamide. For example, the hydrophilic monomer
may comprise protected and unprotected acrylic acid, such as
methacrylic acid, ethacrylic acid, methyl acrylate, ethyl acrylate,
a-butyl acrylate, iso-butyl acrylate, t-butyl acrylate,
2-ethylhexyl acrylate, decyl acrylate, octyl acrylate; methyl
acrylate; methyl methacrylate; methyl ethacrylate; ethyl acrylate;
ethyl methacrylate; ethyl ethacrylate; n-butyl acrylate; n-butyl
methacrylate; n-butyl ethacrylate; 2-ethylhexyl acrylate;
2-ethylhexyl methacrylate; 2-ethylhexyl ethacrylate; N-octyl
acrylamide; 2-methoxyethyl acrylate; 2-hydroxyethyl acrylate;
N,N-dimethylaminoethyl acrylate; N,N-dimethylaminoethyl
methacrylate; acrylic acid; methacrylic acid; N-t-butylacrylamide;
N-sec-butylacrylamide; N,N-dimethylacrylamide;
N,N-dibutylacrylamide; N,N-dihydroxyethyllacrylamide;
2-hydroxyethyl acrylate; 2-hydroxyethyl methacrylate; benzyl
acrylate; 4-butoxycarbonylphenyl acrylate; butyl acrylate;
4-cyanobutyl acrylate; cyclohexyl acrylate; dodecyl acrylate;
2-ethylhexyl acrylate; heptyl acrylate; iso-butyl acrylate;
3-methoxybutyl acrylate; 3-methoxypropyl acrylate; methyl acrylate;
N-butyl acrylamide; N,N-dibutyl acrylamide; ethyl acrylate;
methoxyethyl acrylate; hydroxyethyl acrylate; or
diethyleneglycolethyl acrylate. For example, the hydrophilic
monomer may comprise protected and unprotected acrylic acid, such
as methacrylic acid, ethacrylic acid, methyl acrylate, ethyl
acrylate, a-butyl acrylate, iso-butyl acrylate, t-butyl acrylate,
2-ethylhexyl acrylate, decyl acrylate, octyl acrylate;
2-hydroxyethyl acrylate; N-isopropylacrylamide; ethylene glycol
methacrylate; (polyethylene glycol) methacrylate; or quaternized
dimethylaminoethyl methacrylate. For example, the hydrophilic
monomer may comprise acrylic acid, methacrylic acid, 2-hydroxyethyl
acrylate, acrylamide, vinyl pyrrolidone, vinyl pyridine, styrene
sulphonic acid, PEG-methacrylate, 2-(dimethylamino)ethyl
methacrylate, 2-(trimethylamino)ethyl methacrylate,
2-acrylamido-2-methylpropane sulphonic acid. For example, the
hydrophilic monomer may comprise acrylic acid.
[0126] Suitable monomers that may be used to form a core of a star
macromolecule may include, but are not limited to, a
multifunctional monomer, for example, a hexafunctional monomer, a
pentafunctional monomer, a tetrafunctional monomer, a trifunctional
monomer, or a difunctional monomer. For example, a crosslinker may
be a hydrophobic monomer or a hydrophilic monomer, such as a
hydrophobic multifunctional monomer or a hydrophilic
multifunctional monomer, for example, a hydrophobic difunctional
monomer or a hydrophilic difunctional monomer. For example, the
crosslinker may be a hydrophobic crosslinker, including, but not
limited to, 1,2-divinylbenzene; 1,3-divinylbenzene;
1,4-divinylbenzene; 1,2-ethanediol di(meth)acrylate;
1,3-propanediol di(meth)acrylate; 1,4butanediol di(meth)acrylate;
1,5-hexanediol di(meth)acrylate; divinylbenzene; ethyleneglycol
di(meth)acrylate; di(ethylene glycol) diacrylate (DEGlyDA);
propyleneglycol di(meth)acrylate; butyleneglycol di(meth)acrylate;
triethyleneglycol di(meth)acrylate; polyethyleneglycol
di(meth)acrylate; polypropyleneglycol di(meth)acrylate;
polybutyleneglycol di(meth)acrylate; allyl(meth)acrylate; glycerol
di(meth)acrylate; trimethylolpropane tri(meth)acrylate;
pentaerythritol tetra(meth)acrylate; allyl methacrylate; or allyl
acrylate. For example, the crosslinker may be di(ethylene glycol)
diacrylate (DEGlyDA) or divinylbenzene. For example, the
crosslinker may be divinylbenzene.
[0127] Suitable star macromolecules may include, but are not
limited to, a mikto star macromolecule, a water-soluble star
macromolecule, a gel-forming star macromolecule,
emulsifier/thickening agent star macromolecules or combinations
thereof. In certain embodiments, the star macromolecule may have a
molecular weight of greater than 100,000 g/mol, for example,
between 100,000 g/mol and 2,000,000 g/mol, such as between 125,000
g/mol and 1,750,000 g/mol; between 150,000 g/mol and 1,750,000
g/mol; between 200,000 g/mol and 1,500,000 g/mol; between 225,000
g/mol and 1,250,000 g/mol; between 125,000 g/mol and 1,000,000
g/mol; between 125,000 g/mol and 900,000 g/mol; between 125,000
g/mol and 800,000 g/mol; between 125,000 g/mol and 700,000 g/mol;
between 150,000 g/mol and 650,000 g/mol; between 200,000 g/mol and
600,000 g/mol; between 225,000 g/mol and 650,000 g/mol; between
250,000 g/mol and 550,000 g/mol; between 350,000 g/mol and 500,000
g/mol; between 300,000 g/mol and 500,000 g/mol; or between 350,000
g/mol and 750,000 g/mol.
[0128] Suitable star macromolecules may have a polydispersity index
(PDI) of less than 2.5, for example, a PDI of less that 2.0, such
as less than 1.7. For example, a star macromolecule may have a PDI
of between 1.0 to 2.5, such as between 1.0 and 2.3; between 1.0 and
2.0; between 1.0 and 1.9; between 1.0 and 1.8; between 1.0 and 1.7;
between 1.0 and 1.6; between 1.0 and 1.5; between 1.0 and 1.4;
between 1.0 and 1.3; between 1.0 and 1.2; between 1.0 and 1.1;
between 1.05 and 1.75; between 1.1 and 1.7; between 1.15 and 1.65;
or between 1.15 and 1.55.
[0129] Suitable star macromolecules may comprise arms that are of
the same type or a different type and are homopolymeric,
copolymeric, comprise multiple block segment, random segments,
gradient segments and or no particular segments. In certain
embodiments, the star macromolecule may comprise, for example, one
or more arm-types, such as, two or more, three or more, four or
more, or five or more arm-types. Suitable arm types may include,
but are not limited to, homopolymeric arms, copolymeric arms, such
as random copolymeric arms or block copolymeric arms, or
combinations thereof. For example, a star macromolecule may
comprise homopolymeric arms and copolymeric arms, such as block
copolymeric arms. Suitable arm types may also include, but are not
limited to, hydrophilic arms, hydrophobic arms, or amphiphilic
arms. In certain embodiments, a star macromolecule arm may comprise
hydrophilic polymeric segments comprising hydrophilic monomeric
residues, hydrophobic polymeric segments comprising hydrophobic
monomeric residues, amphiphilic polymeric segments comprising
amphiphilic monomeric residues, or combinations thereof. For
example, in certain embodiments, a star macromolecule may comprise
homopolymeric arms and copolymeric arms, such as hydrophilic
homopolymeric arms and copolymeric arms comprising hydrophilic
polymeric segments and hydrophobic polymeric segments.
[0130] Suitable star macromolecules may also comprise arms that are
covalently linked to the core of the star macromolecule. In certain
embodiments, the arms of a star macromolecule may be covalently
linked to the core of the star macromolecule via crosslinking, such
as crosslinking with a crosslinker, for example, a hydrophobic
difunctional crosslinker or a hydrophilic difunctional crosslinker.
For example, arms of a star macromolecule, such as homopolymeric
arms and block copolymeric arms of a mikto star macromolecule, may
be covalently linked together to form a core by crosslinking an end
of the arms with a crosslinker, such as with a hydrophobic
difunctional crosslinker or a hydrophilic difunctional
crosslinker.
[0131] Suitable star macromolecules may also comprise arms of
varying length and/or degree of polymerization. In certain
embodiments, for example, a star macromolecule may comprise
homopolymeric arms and block copolymeric arms, wherein the
homopolymeric arms of a shorter length and/or a lesser degree of
polymerization in relation to the block copolymeric arms. In
certain embodiments, for example, a star macromolecule may comprise
homopolymeric arms and block copolymeric arms, wherein the block
copolymeric arms of a longer length and/or a greater degree of
polymerization in relation to the homopolymeric arms. In certain
embodiments, a star macromolecule may comprise hydrophilic
homopolymeric arms and block copolymeric arms, comprising
hydrophobic polymeric segments distal to the star core and
hydrophilic polymeric segments that are proximal to the core of the
star, wherein a distal portion of the hydrophilic polymeric
segments of the copolymeric arm extends beyond a distal portion of
the hydrophilic homopolymeric arms. For example, a star
macromolecule may comprise hydrophilic homopolymeric arms
comprising polymerized hydrophilic monomeric residues and block
copolymeric arms comprising hydrophobic polymeric segments distal
to the core of the star and hydrophilic polymeric segments that are
proximal to the core of the star, wherein the distal hydrophobic
polymeric segments extend beyond the most distal portion, in
relation to the core, of the hydrophilic homopolymeric arms, and/or
wherein a distal portion of the proximal hydrophilic polymeric
segments of the copolymeric arm extend beyond the most distal
portion, in relation to the core, of the hydrophilic homopolymeric
arms. In certain embodiments, a star macromolecule may comprise
hydrophilic homopolymeric arms and block copolymeric arms,
comprising hydrophobic polymeric segments distal to the star core
and hydrophilic polymeric segments that are proximal to the star
core, wherein the degree of polymerization of the hydrophilic
polymeric segments of the copolymeric arm is greater than, for
example, 20% greater than, such as between 30% to 300% greater
than, between 40% to 250%, between 50% to 200%, or between 75% to
250% greater than, the degree of polymerization of the hydrophilic
homopolymeric arms, such that a distal portion of the hydrophilic
polymeric segments of the copolymeric arm extends beyond the a
distal portion of the hydrophilic homopolymeric arms.
[0132] In certain embodiments, a star macromolecule may comprise
hydrophilic homopolymeric arms comprising polymerized hydrophilic
monomeric residues and block copolymeric arms comprising
hydrophobic polymeric segments distal to the core of the star and
hydrophilic polymeric segments proximal to the core of the star,
wherein the polymerized hydrophilic monomeric residues of the
homopolymeric arm and the hydrophilic polymeric segments of the
copolymeric arm may be derived from the same hydrophilic monomers,
and may have the same or different degree of polymerization, for
example, a degree of polymerization of between 50 to 500 monomeric
residues, such as, between 50 to 400 monomeric residues; between 50
to 300 monomeric residues; between 50 to 200 monomeric residues;
between 100 to 250 monomeric residues; between 125 to 175 monomeric
residues; or between 150 to 300 monomeric residues. For example, a
star macromolecule may comprise hydrophilic homopolymeric arms
comprising polymerized hydrophilic monomeric residues and block
copolymeric arms comprising hydrophobic polymeric segments distal
to the core of the star and hydrophilic polymeric segments proximal
to the core of the star, wherein the polymerized hydrophilic
monomeric residues of the homopolymeric arm and the hydrophilic
polymeric segments of the copolymeric arm may be derived from the
same hydrophilic monomers, and may have the same degree of
polymerization, and wherein the hydrophibic polymeric segments of
the copolymeric arm may have a degree of polymerization of between
1 to 60 monomeric residues, such as between 1 to 50 monomeric
residues; between 1 to 45 monomeric residues; between 5 to 40
monomeric residues; between 8 to 35 monomeric residues; between 10
to 30 monomeric residues; between 12 to 25 monomeric residues;
between 14 to 20 monomeric residues; between 15 to 30 monomeric
residues; or between 5 to 20 monomeric residues.
[0133] Suitable star macromolecules may have a wide range of total
number of arms, for example, a star macromolecule may comprise
greater than 15 arms. For example, a suitable star macromolecule
may comprise between 15 and 100 arms, such as between 15 and 90
arms; between 15 and 80 arms; between 15 and 70 arms; between 15
and 60 arms; between 15 and 50 arms; between 20 and 50 arms;
between 25 and 45 arms; between 25 and 35 arms; between 30 and 45
arms; or between 30 and 50 arms.
[0134] Suitable star macromolecules may have more than one arm
type, such as two or more different arm types, where in a molar
ratio of the different arm types may be between 20:1 and 1:1. For
example, a star macromolecule comprising two different arm types,
such as a homopolymeric arm, for example, a hydrophilic
homopolymeric arm, and a copolymeric arm, for example, a
copolymeric arm comprising hydrophilic polymeric segments and
hydrophobic polymeric segments, may have a molar ratio of the two
different arm types between 20:1 to 2:1, such as between 15:1 to
2:1; between 10:1 to 2:1; between 9:1 to 2:1; between 8:1 to 2:1;
between 7:1 to 2:1; between 6:1 to 2:1; between 5:1 to 2:1; between
4:1 to 2:1; between 3:1 to 2:1; between 2:1 to 1:1; between 8:1 to
3:1; between 7:1 to 2:1; or between 5:1 to 3:1.
[0135] Suitable star macromolecules may include, but is not limited
to, comprising arms having a molecular weight of greater than
10,000 g/mol. For example, a star macromolecule may comprise arms
having a molecular weight of between 10,000 g/mol and 200,000
g/mol, such as between 10,000 g/mol and 175,000 g/mol; between
10,000 g/mol and 150,000 g/mol; between 10,000 g/mol and 125,000
g/mol; between 10,000 g/mol and 100,000 g/mol; between 10,000 g/mol
and 90,000 g/mol; between 10,000 g/mol and 80,000 g/mol; between
10,000 g/mol and 70,000 g/mol; between 60,000 g/mol and 50,000
g/mol; between 10,000 g/mol and 40,000 g/mol; between 10,000 g/mol
and 30,000 g/mol; between 10,000 g/mol and 20,000 g/mol; between
20,000 g/mol and 175,000 g/mol; between 20,000 g/mol and 100,000
g/mol; between 20,000 g/mol and 75,000 g/mol; between 20,000 g/mol
and 50,000 g/mol; between 15,000 g/mol and 45,000 g/mol; or between
15,000 g/mol and 30,000 g/mol.
[0136] Suitable arms of a star macromolecule may include, but is
not limited to, arms having an HLB value of at least 17 (wherein
the HLB is calculated per the formula set forth in the test
procedures). For example, suitable arms of a star macromolecule may
have an HLB value of greater than 17.25, such as greater than 18.5;
at least 19; between 17.5 to 20; between 17.5 to 19.5; between 18
to 20; between 18.5 to 20; between 19 to 20; between 19.5 to 20;
between 18 to 19.5; between 18.5 to 19.75; between 18.2 to 19.2; or
between 18.75 to 19.5.
[0137] Suitable hydrophobic polymeric segments of a copolymeric arm
of a star macromolecule may include, but is not limited to,
hydrophobic polymeric segments having an HLB value of less than 8.
For example, suitable hydrophobic polymeric segments may have an
HLB value of less than 7, such as less than 6; less than 5; less
than 4; less than 3; less than 2; or about 1.
[0138] Suitable arms of a star macromolecule may include, but is
not limited to, arms having a polydispersity index (PDI) value of
less than 2.5. For example, suitable arms of a star macromolecule
may have PDI value of less than 2.25, such as less that 2.0; less
than 1.7; between 1.0 to 2.5, such as between 1.0 and 2.3; between
1.0 and 2.0; between 1.0 and 1.9; between 1.0 and 1.8; between 1.0
and 1.7; between 1.0 and 1.6; between 1.0 and 1.5; between 1.0 and
1.4; between 1.0 and 1.3; between 1.0 and 1.2; between 1.0 and 1.1;
between 1.05 and 1.75; between 1.1 and 1.7; between 1.15 and 1.65;
or between 1.15 and 1.55.
[0139] Suitable cores of a star macromolecule may be formed by or
derived from, but is not limited to, crosslinking of a plurality of
arms and a crosslinker. For example, a core may be formed by or
derived from crosslinking of a plurality of homopolymeric arms and
a plurality of copolymeric arms with a crosslinker, such as a
mutlifunctional monomer crosslinker, for example, a hydrophobic
difunctional monomer crosslinker. In certain embodiments, the core
may be formed or derived from crosslinking a plurality of
hydrophilic homopolymeric arms and a plurality of copolymeric arms,
comprising block hydrophilic polymeric segments and block
hydrophobic polymeric segments, with a crosslinker, such as a
hydrophobic difunctional monomer crosslinker, for example
divinylbenzene, wherein the molar ratio of the homopolymeric arms
to the copolymeric arms may be between 20:1 to 2:1.
[0140] Suitable star macromolecules may include, but is not limited
to, comprising a core having a molecular weight of greater than
3,000 g/mol. For example, a star macromolecule may comprise a core
having a molecular weight of between 3,000 g/mol and 50,000 g/mol,
such as between 3,000 g/mol and 45,000 g/mol; between 3,000 g/mol
and 40,000 g/mol; between 3,000 g/mol and 30,000 g/mol; between
3,000 g/mol and 20,000 g/mol; between 3,000 g/mol and 15,000 g/mol;
between 5,000 g/mol and 40,000 g/mol; between 6,000 g/mol and
30,000 g/mol; between 7,000 g/mol and 25,000 g/mol; between 8,000
g/mol and 20,000 g/mol; between 5,000 g/mol and 15,000 g/mol;
between 7,000 g/mol and 12,000 g/mol; between 5,000 g/mol and 9,000
g/mol; between 8,000 g/mol and 10,000 g/mol; or between 9,000 g/mol
and 15,000 g/mol.
[0141] Suitable star macromolecules may be used to form a clear,
homogeneous gel when dissolved in water at a concentration of at
least 0.05 wt. % at a pH of about 7.5 at STP. For example, a star
macromolecule may form a clear, homogeneous gel when dissolved in
water at a concentration of between 0.05 wt. % to 3 wt. %, such as
between 0.1 wt. % to 2.5 wt. %; between 0.1 wt. % to 2 wt. %;
between 0.2 wt. % to 2.0 wt. %; between 0.2 wt. % to 1.5 wt. %;
between 0.2 wt. % to 1.0 wt. %; between 0.2 wt. % to 2.5 wt. %;
between 0.3 wt. % to 2.5 wt. %; between 0.4 wt. % to 2.0 wt. %;
between 0.5 wt. % to 2.0 wt. %; between 0.6 wt. % to 2.0 wt. %;
between 0.7 wt. % to 1.5 wt. %; between 0.8 wt. % to 1.2 wt. %;
between 0.9 wt. % to 1.1 wt. %; between 0.5 wt. % to 2.5 wt. %;
between 0.75 wt. % to 1.5 wt. %; or between 0.8 wt. % to 1.6 wt.
%.
[0142] Suitable star macromolecules, in accordance with the pH
Efficiency Range Test Procedure described below herein, may be used
to form a clear, homogeneous gel, wherein the star macromolecule at
a concentration of 0.4 wt. %, may have a viscosity of at least
20,000 cP, at a pH of between about 4 to about 12, for example, at
a pH of between about 5 to about 11.5 such as at a pH of between
about 5 to about 11; between about 5 to about 10.5; between about 5
to about 10; between about 5 to about 9.5; between about 5 to about
9; between about 5 to about 8.5; between about 5 to about 8;
between about 6 to about 11; between about 5.5 to about 10; between
about 6 to about 9; between about 6.5 to about 8.5; between about 7
to about 8; between about 7.5 to about 8.5; or between about 6.5 to
about 7.5.
[0143] In certain embodiments, for example, suitable star
macromolecules, in accordance with the pH Efficiency Range Test
Procedure described below herein, may be used to form a clear,
homogeneous gel, wherein the star macromolecule at a concentration
of 0.4 wt. %, may have a viscosity of at least 20,000 cP at a pH
between about 5.5 to about 11. For example, at a pH between about
5.5 to about 11 may have a viscosity of at least 30,000 cP, such
as, at least 40,000 cP; between 20,000 cP to 250,000 cP; between
20,000 cP to 250,000 cP; between 20,000 cP to 225,000 cP; between
20,000 cP to 200,000 cP; between 20,000 cP to 175,000 cP; between
20,000 cP to 150,000 cP; between 20,000 cP to 125,000 cP; between
30,000 cP to 250,000 cP; between 30,000 cP to 200,000 cP; between
40,000 cP to 175,000 cP; or between 40,000 cP to 150,000 cP. For
example, a gel at a pH between about 6 to about 11 may have a
viscosity of at least 20,000 cP, such as, at least 30,000 cP; at
least 40,000 cP; between 20,000 cP to 250,000 cP; between 20,000 cP
to 250,000 cP; between 20,000 cP to 225,000 cP; between 20,000 cP
to 200,000 cP; between 20,000 cP to 175,000 cP; between 20,000 cP
to 150,000 cP; between 20,000 cP to 125,000 cP; between 30,000 cP
to 250,000 cP; between 30,000 cP to 200,000 cP; between 40,000 cP
to 175,000 cP; or between 40,000 cP to 150,000 cP. For example, at
a pH between about 7 to about 10.5 may have a viscosity of at least
60,000 cP, such as at least 70,000 cP; between 60,000 cP to 250,000
cP; between 60,000 cP to 225,000 cP; between 60,000 cP to 200,000
cP; between 60,000 cP to 175,000 cP; between 60,000 cP to 150,000
cP; between 60,000 cP to 125,000 cP; between 60,000 cP to 115,000
cP; between 60,000 cP to 105,000 cP; or between 60,000 cP to
100,000 cP. For example, at a pH between about 7.5 to about 9.0 may
have a viscosity of at least 95,000 cP, such as at least 100,000
cP; between 95,000 cP to 250,000 cP; between 95,000 cP to 225,000
cP; between 95,000 cP to 200,000 cP; between 95,000 cP to 175,000
cP; between 95,000 cP to 150,000 cP; between 95,000 cP to 125,000
cP; between 95,000 cP to 115,000 cP; or between 95,000 cP to
105,000 cP.
[0144] Suitable star macromolecules, in accordance with the Dynamic
Viscosity & Shear-Thinning Test Procedure described below
herein, may be used to form a clear, homogeneous gel, wherein the
star macromolecule at a concentration of 0.4 wt. %, may have a
viscosity of less than 5,000 cP at a shear rate of 4 sec.sup.-1,
such as a viscosity of less than 4,000 cP. For example, the star
macromolecule at a concentration of 0.4 wt. %, may have a viscosity
have a viscosity of less than 5,000 cP at a shear rate of 6
sec.sup.-1, such as a viscosity of less than 4,000 cP or less than
3,000 cP. For example, a gel may have a viscosity of less than
15,000 cP at a shear rate of 0.7 sec.sup.-1, such as a viscosity of
less than 14,000 cP or less than 13,000 cP. Suitable gels may
include, but is not limited to, gels having shear-thinning value of
at least 5, such as a shear-thinning value of at least 6, or
between 5 to 15, such as between 5 to 15; between 7 to 12; between
8 to 10; or between 6 to 13.
[0145] Suitable star macromolecules, in accordance with the Dynamic
Viscosity & Shear-Thinning Test Procedure described below
herein, include those that have a shear-thinning value of at least
15, such as a shear-thinning value of between 15 to 100, such as
between 15 to 90; between 20 to 80; between 25 to 70; between 25 to
50; or between 30 to 40.
[0146] Suitable star macromolecules, in accordance with the
Salt-Induced Break Test Procedure described below herein, include
those that have a salt-induced break value of at least 50%, such as
a salt-induced break value of between 65% to 100%, such as between
75% to 100%; between 80% to 95%; between 75% to 90%; between 50% to
85%; between 70% to 95%; or between 60% to 100%.
[0147] Suitable star macromolecules, in accordance with the pH
Efficiency Range Test Procedure described below herein, include
those that have a pH-induced break value of at least 15%, such as a
pH-induced break value of between 15% to 100%, such as between 25%
to 100%; between 30% to 95%; between 40% to 90%; between 50% to
85%; between 70% to 95%; between 80% to 97%; between 90% to 99%;
between 95% to 100%; or between 60% to 100%.
[0148] Suitable star macromolecules, in accordance with the Dynamic
Viscosity & Shear-Thinning Test Procedure described below
herein, include those that have a dynamic viscosity value, of
greater than 20,000 cP at 1 rpm, and at a concentration of 0.2 wt.
%, such as a dynamic viscosity value of greater than 24,000 cP;
greater than 28,000 cP; or greater than 30,000 cP at a
concentration of 0.2 wt. %.
[0149] Suitable emulsions may include, but is not limited to,
emulsions that are emulsifier-free and wherein the emulsion is
thickened by a star macromolecule. For example, the star
macromolecule that may be included in the emulsifier-free emulsion
may be a water-soluble star macromolecule, wherein the
water-soluble star macromolecule emulsifies the emulsifier-free
emulsion.
[0150] Suitable star macromolecules, include star macromolecules
that have an emulsion value of greater than 60 minutes, for
example, greater than 3 hours, such as greater than 6 hours;
greater than 10 hours; greater than 20 hours; greater than 40
hours; or greater than 100 hours.
[0151] Suitable star macromolecules, according to Formula X, may
include star macromolecules wherein P1, P2, and/or P3 comprise
hydrophobic monomers, hydrophilic monomers, amphiphilic monomers,
or combinations thereof. For example, P1 comprises hydrophobic
monomers, P2 comprises hydrophilic monomers, and P3 comprises
hydrophilic monomers. For example, star macromolecules, according
to Formula X, may include star macromolecules wherein q1 may have a
value of between 1 to 100, for example, between 1 to 60, such as,
between 1 to 45; between 5 to 40; between 8 to 35; between 10 to
30; between 12 to 25; between 14 to 20; between 15 to 30; or
between 5 to 20; and q2 and/or q3 have a value of between 50 to
500, for example, between 50 to 400, such as, between 50 to 300;
between 50 to 200; between 100 to 250; between 125 to 175; or
between 150 to 300. For example, star macromolecules, according to
Formula X, may include star macromolecules wherein r or t, or the
sum of r and t, may be greater than 15, such as between 15 and 100;
between 15 and 90; between 15 and 80; between 15 and 70; between 15
and 60; between 15 and 50; between 20 and 50; between 25 and 45;
between 25 and 35; between 30 and 45; or between 30 and 50. For
example, star macromolecules, according to Formula X, may include
star macromolecules wherein the molar ratio of r to t is in the
range of between 20:1 to 2:1, such as between 15:1 to 2:1; between
10:1 to 2:1; between 9:1 to 2:1; between 8:1 to 2:1; between 7:1 to
2:1; between 6:1 to 2:1; between 5:1 to 2:1; between 4:1 to 2:1;
between 3:1 to 2:1; between 2:1 to 1:1; between 8:1 to 3:1; between
7:1 to 2:1; or between 5:1 to 3:1. For example, star
macromolecules, according to Formula X, may include star
macromolecules wherein the core may be derived from crosslinker
monomers, such as hydrophobic crosslinker monomers. For example,
star macromolecules, according to Formula X, may include star
macromolecules wherein the core may comprise crosslinker
monomereric residues, such as hydrophobic crosslinker monomeric
residues. For example, star macromolecules, according to Formula X,
may include star macromolecules wherein the arm
[(P1).sub.q1-(P2).sub.q2].sub.t may be homopolymeric or
copolymeric, such as block copolymeric.
[0152] Suitable star macromolecules, may include, but is not
limited to, star macromolecules formed by crosslinking the arms
with a crosslinker, such as crosslinking homopolymeric arms and
block copolymeric arms with a hydrophobic crosslinker. For example,
the homopolymeric arms and the copolymeric arms of a star
macromolecule may be covalently attached to the core via
crosslinkage with a crosslinker. For example, a core of a prepared
star macromolecule may be prepared by crosslinking an end of a
homopolymeric arm with an end of a copolymeric arm, such as an end
of a hydrophilic homopolymeric arm with a hydrophilic end of a
copolymeric arm. For example, the core of a prepared star
macromolecules may be formed by crosslinking an ATRP-functional
terminal group end of a homopolymeric arm with an ATRP-functional
terminal group end of a copolymeric arm.
[0153] Suitable initiators that may be used to form the star
macromolecules disclosed herein, may include, but is not limited
to, nitroxide initiators, such as stable nitroxide initiators, for
example, 2,2,6,6-Tetramethylpiperidine-1-oxyl, sometimes called
TEMPO; transition metal complexes, such cobalt containing
complexes; ATRP initiators, comprising halides, such as, bromide,
chloride, or iodide, and transition metal sources, such as, copper,
iron, ruthenium transition metal sources; iodide with RCTP
catalysts, such as germanium or tin catalysts; RAFT initiators,
such as dithioesters, dithiocarbamates, or xanthates; ITP
catalysts, comprising iodides; tellurium compounds (e.g., TERP);
stibine compounds (e.g., SBRP); or bismuth compounds (e.g., BIRP).
For example, in certain embodiments, an initiator may further
comprise a monomeric residue, a polymeric segment comprising
monomeric residues, or a small-molecule. For example, in certain
embodiments, an initiator may comprise an ATRP initiator, wherein
the ATRP initiator serves as a terminal functional group. For
example, in certain embodiments, an initiator may comprise an
ATRP-functional terminal group, comprising an ATRP initiator, such
as halides and transition metal sources.
[0154] Suitable materials comprising the star macromolecules
disclosed herein, include, but is not limited to, lotions, such as
cosmetic lotions, personal care lotions, body lotions,
emulsifier-free body lotions; serums, such as anti-aging serums;
sunscreens, such as SPF 30 sunscreens, SPF 35 sunscreens, SPF 40
sunscreens, SPF 50 sunscreens; creams, such as face-creams,
cosmetic creams; hair products, such as shampoos, hair styling
products, hair sprays, mousses, hair gels, hair conditioners, bath
preparations; gels, such as cosmetic gels or personal care gels;
skin application products, such as ointments, deodorants, personal
care powders, skin cleansers, skin conditioners, skin emollients,
skin moisturizers, skin wipes, shaving preparations; fabric
softeners; dental impression materials; or variations thereof.
[0155] Suitable materials comprising an emulsifier-free emulsion,
wherein the emulsion is thickened by a star macromolecule disclosed
herein, may include, but is not limited to, lotions, such as
cosmetic lotions, personal care lotions, body lotions,
emulsifier-free body lotions; serums, such as anti-aging serums;
sunscreens, such as SPF 30 sunscreens, SPF 35 sunscreens, SPF 40
sunscreens, SPF 50 sunscreens; creams, such as face-creams,
cosmetic creams; hair products, such as shampoos, hair styling
products, hair sprays, mousses, hair gels, hair conditioners, bath
preparations; gels, such as cosmetic gels or personal care gels;
skin application products, such as ointments, deodorants, personal
care powders, skin cleansers, skin conditioners, skin emollients,
skin moisturizers, skin wipes, shaving preparations; fabric
softeners; dental impression materials; or variations thereof.
[0156] In an embodiment, examples of suitable lotion formulations
include body lotion formulations, comprising an emulsifier-free
emulsion, wherein the emulsion is thickened by a star macromolecule
disclosed herein, may include, but is not limited to, formulations
comprising one or more of the following: Deionized Water; Disodium
EDTA; 1,3-Butylene Glycol; Glycerin; Allantoin; Urea; TEA 99%;
Edible Olive Oil (N.F.); Shea Butter; Wickenol 171; Squalane;
Crodamol CAP; Crodamol STS; Crodacol C; Tween 20; Lipo GMS 470; PEG
100 Stearate; Cetyl Palmitate; Crodamol PTIS; Crodafos CES; DC
1401; Evening Primrose Oil; Vitamin E Acetate; D-Panthenol;
Distinctive HA2; Diocide; or derivatives or combinations
thereof.
[0157] In an embodiment, examples of suitable lotion formulations
include emulsifier-free personal care lotion formulations,
comprising an emulsifier-free emulsion, wherein the emulsion is
thickened by a star macromolecule disclosed herein, may include,
but is not limited to, formulations comprising one or more of the
following: Deionized Water; Disodium EDTA; 1,3-Butylene Glycol;
Glycerin; Allantoin; Urea; TEA 99%; Edible Olive Oil (N.F.);
Wickenol 171; Myritol 318; Squalane; Crodamol PTIS; Isododecane;
Evening Primrose Oil; Vitamin E Acetate; D-Panthenol; Distinctive
HA2; Diocide; or derivatives or combinations thereof.
[0158] In an embodiment, examples of suitable formulations include
serum formulations, such as anti-aging serum formulations,
comprising an emulsifier-free emulsion, wherein the emulsion is
thickened by a star macromolecule disclosed herein, may include,
but is not limited to, formulations comprising one or more of the
following: Deionized Water; Disodium EDTA; Glycerin; 1,3-Butylene
Glycol; Caffeine; Allantoin; Triethanolamine 99%; Crodamol STS;
Myritol 318; Wickenol 171; Tween 20; Crodaphos CES; BVOSC; Vitamin
E Acetate; Vitamin A Palmitate; Vitamin D3; Gransil IDS;
D-Panthenol; DC Upregulex; DC Skin Bright MG; Actiphyte of Japanese
Green Tea G; Actiphyte of Grape Seed G; DC Hydroglide; Diocide; or
derivatives or combinations thereof.
[0159] In an embodiment, suitable formulations include sunscreen
formulations, comprising an emulsifier-free emulsion, wherein the
emulsion is thickened by a star macromolecule disclosed herein, may
include, but is not limited to, formulations comprising one or more
of the following: Deionized Water; Disodium EDTA; Glycerin;
Triethanolamine 99%; Homomethyl Salicylate; Ethylhexyl Salicylate;
Avobenzone; Benzophenone 3; Myritol 318; Lexfeel 7; Octocrylene;
Cetyl Alcohol; PEG-15 Cocamine; Lipo GMS 470; Crodafos CS-20;
Vitamin E Acetate; Aloe Vera Leaf Juice; Diocide; or derivatives or
combinations thereof.
[0160] In an embodiment, examples of suitable formulations include
face cream formulations, comprising an emulsifier-free emulsion,
wherein the emulsion is thickened by a star macromolecule disclosed
herein, may include, but is not limited to, formulations comprising
one or more of the following: Deionized Water; Disodium EDTA; 1,3
Butylene Glycol; Glycerin; Caffeine; Allantoin; Triethanolamine
99%; Myritol 318; Octyl Palmitate; Wickenol 171; Crodaphos CES;
Cetyl Alcohol; Pationic SSL; Cetyl Palmitate; Vitamin E Acetate;
BVOSC; Lexfeel 7; Lipo GMS 470; Vitamin A/D3 in Corn Oil; DC 1401;
Actiphyte of Japanese Green Tea G; Actiphyte of Grape Seed G; DC
Hydroglide; Diocide; or derivatives or combinations thereof.
Synthesis of the Rheology Modifier
[0161] Although any conventional method can be used for the
synthesis of the multi-arm star macromolecules of the invention,
free radical polymerization is the preferred and living/controlled
radical polymerization (CRP) is the most preferred process.
[0162] CRP has emerged during the past decade as one of the most
robust and powerful techniques for polymer synthesis, as it
combines some of the desirable attributes of conventional free
radical polymerization (e.g., the ability to polymerize a wide
range of monomers, tolerance of various functionality in monomer
and solvent, compatibility with simple industrially viable reaction
conditions) with the advantages of living ionic polymerization
techniques (e.g., preparation of low polydispersity index
(PDI=M.sub.w/M.sub.n) polymer and chain-end functionalized homo-
and block (co)polymers). The basic concept behind the various CRP
procedures is the reversible activation of a dormant species to
form the propagating radical. A dynamic and rapid equilibrium
between the dormant and the active species minimizes the
probability of bimolecular radical termination reactions and
provides an equal opportunity for propagation to all polymer (or
dormant) chains.
[0163] CRP procedures can be classified into three main groups
based on the mechanism of reversible activation: (a) stable free
radical polymerization (SFRP, Scheme 1a), (b) degenerative chain
transfer polymerization (DT, Scheme 1b), and (c) atom transfer
radical polymerization (ATRP, Scheme 1c).
##STR00001##
[0164] As shown in Scheme 1 various capping agents, X, are used for
the different CRP procedures and they are summarized in Scheme 2.
They include stable nitroxides (Scheme 2a), transition metal
complexes (Scheme 2b), halides with transition metal catalysts
(Scheme 2c), iodine with catalysts (Scheme 2d), sulfur compounds
(Scheme 2e), iodine (Scheme 2f), and organometal compounds (Scheme
2g).
##STR00002##
[0165] Star polymers are nano-scale materials with a globular
shape. As illustrated in FIG. 1, stars formed by the "arm first"
procedure, discussed in detail below, can have a crosslinked core
and can optionally possess multiple segmented arms of similar
composition. Stars can be designed as homo-arm stars or mikto-arm
stars. FIG. 1A represents a homo-arm star with block copolymer
arms. Mikto-arm stars have arms with different composition or
different molecular weight; FIGS. 1B and 1C. Both homo-arm stars
and mikto-arm stars can optionally possess a high-density of
peripheral functionality.
[0166] Synthesis of star polymers of the invention can be
accomplished by "living" polymerization techniques via one of three
strategies: 1) core-first" which is accomplished by growing arms
from a multifunctional initiator; 2) "coupling-onto" involving
attaching preformed arms onto a multifunctional core and the 3)
arm-first" method which involves cross-linking preformed linear arm
precursors using a divinyl compound
[0167] While all above controlled polymerization procedures are
suitable for preparation of an embodiment of the disclosed self
assembling star macromolecules. Other embodiments are also
exemplified, for example, the preparation of the self assembling
multi-arm stars with narrow MWD, in contrast to prior art using
ATRP. The reason for the use of the Controlled Radical
Polymerization process (CRP) known as ATRP; disclosed in U.S. Pat.
Nos. 5,763,546; 5,807,937; 5,789,487; 5,945,491; 6,111,022;
6,121,371; 6,124,411: 6,162,882: and U.S. patent application Ser.
Nos. 09/034,187; 09/018,554; 09/359,359; 09/359,591; 09/369,157;
09/126,768 and 09/534,827, and discussed in numerous publications
listed elsewhere with Matyjaszewski as co-author, which are hereby
incorporated into this application, is that convenient procedures
were described for the preparation of polymers displaying control
over the polymer molecular weight, molecular weight distribution,
composition, architecture, functionality and the preparation of
molecular composites and tethered polymeric structures comprising
radically (co)polymerizable monomers, and the preparation of
controllable macromolecular structures under mild reaction
conditions.
[0168] An aspect of the present invention relates to the
preparation and use of multi-arm star macromolecules by an "arm
first" approach, discussed by Gao, H.; Matyjaszewski, K. JACS;
2007, 129, 11828. The paper and cited references therein are hereby
incorporated by reference to describe the fundamentals of the
synthetic procedure. The supplemental information available within
the cited reference provides a procedure for calculation of the
number of arms in the formed star macromolecule.
[0169] It is expected that biphasic systems such as a miniemulsion
or an ab initio emulsion system would also be suitable for this
procedure since miniemulsion systems have been shown to function as
dispersed bulk reactors [Min, K.; Gao, H.; Matyjaszewski, K.
Journal of the American Chemical Society 2005, 127, 3825-3830] with
the added advantage of minimizing core-core coupling reactions
based on compartmentalization considerations.
[0170] In one embodiment star macromolecules are prepared with
composition and molecular weight of each segment predetermined to
perform as rheology modifiers in aqueous based solutions. The first
formed segmented linear (co)polymer chains are chain extended with
a crosslinker forming a crosslinked core.
[0171] In another embodiment a simple industrially scalable process
for the preparation of star macromolecules is provided wherein the
arms comprise segments selected to induce self assembly and wherein
the self assemblable star macromolecules are suitable for use as
rheology control agents in waterborne and solvent-borne coatings,
adhesives, cosmetics and personal care compositions.
[0172] The invention is not limited to the specific compositions,
components or process steps disclosed herein as such may vary.
[0173] It is also to be understood that the terminology used herein
is only for the purpose of describing the particular embodiments
and is not intended to be limiting.
[0174] The procedure for the preparation of star macromolecules may
be exemplified by (co)polymerization of linear macromolecules,
including macroinitiators (MI) and macromonomers (MMs), with a
multi-vinyl cross-linker, a divinyl crosslinker is employed in the
exemplary examples disclosed herein, to form a core of the star.
The formation of the core of the star can also be formed through a
copolymerization reaction wherein a monovinyl monomer is added to
expand the free volume of the core to allow incorporation of
additional arms into the congested core forming environment or to
provide sufficient free volume within the core of the star to
encapsulate functional small molecules. A molecule that functions
as an initiator and a monomer, an inimer, can also be employed in
the preparation of the core of the star macromolecule. When added
to the reaction it functions to form a three arm branch in the core
of the molecule and hence acts in a manner similar to the added
monomer to increase the free volume within the star core.
[0175] The volume fraction of the core of the star can be
controlled by appropriate selection of the crosslinker molecule or
by conducting a copolymerization between the crosslinker and a
vinyl monomer or an inimer. The composition of the core can be
selected to provide an environment to encapsulate small molecules,
such as fragrances, and control the rate of diffusion of the
fragrance from the self assembled thickening agent after deposition
on a part of the human body.
[0176] The core of the star polymers may contain additional
functionality. This additional functionality can be of direct
utility in certain applications or can be employed to tether or
encapsulate further functional materials such as fragrances,
stimuli responsive molecules or bio-responsive molecules to the
core of the star by chemical or physical interactions.
[0177] The star macromolecules can be prepared in dilute solution
when reaction conditions and crosslinker are chosen to avoid or
reduce star-star coupling reactions.
[0178] The synthesis of multi-arm star polymers where the periphery
of the star polymers contains additional functionality is possible.
This functionality can be introduced by use of an initiator
comprising the desired .alpha.-functionality in the residue of the
low molecular weight initiator remaining at the .alpha.-chain end
of each arm.
[0179] An embodiment of the present invention can be exemplified by
the preparation of a multi-arm star macromolecule wherein the
number of arms in the star macromolecule is between 5 and 500,
preferentially between 10 and 250, with segments selected to induce
self assembly when the star macromolecule is dispersed in a liquid
wherein the self assemblable star macromolecules are suitable for
use as thickening agents or rheology modifiers in cosmetic and
personal care compositions at low concentrations of the solid in
the thickened solution, preferably less than 5 wt %, and optimally
less than 1 wt %. The dispersion medium can comprise aqueous based
systems or oil based systems.
[0180] The structure of an exemplary new thickening agent, or
rheology modifier, of one embodiment, is a multiarm segmented star
macromolecule wherein the core is prepared by controlled radical
polymerization using an arm-first method. Scheme 3 provides a
simple four step procedure that can be employed for preparation of
an initial non-limiting exemplifying case the procedure is an atom
transfer radical polymerization arm first macroinitiator method. In
this approach the precursor of the arm(s) comprise a linear
copolymer chain with a single terminal activatable group, as will
be understood by one skilled in the art, having this disclosure as
a guide, the activatable arm precursor will have a .omega.-terminal
functionality that under the conditions of the polymerization
procedure can reversibly generate a radical. Scheme 3 illustrates
the concept by sequential polymerization of styrene and tBA. These
monomers are purely exemplary monomers and should not limit the
applicability of the procedure in any manner since other monomers
of similar phylicity can be employed. In Scheme 3 the polystyrene
segment can be considered the outer shell of the star and the final
poly(acrylic acid) segments the inner water soluble shell and the
segment formed by chain extending the linear copolymer
macroinitiators by reaction with the divinylbenzene crosslinker the
core of the star.
##STR00003##
[0181] Similar structures can also be prepared using the
macromonomer method or a combination of the macromonomer and
macroinitiator method in a controlled polymerization process, or
even through free radical copolymerization conducted on
macromonomers, as known to those skilled in the art. [Gao, H.;
Matyjaszewski, K. Chem.--Eur. J. 2009, 15, 6107-6111.]
[0182] Both the macromonomer and macroinitiator procedures allow
incorporation of polymer segments prepared by procedures other than
CRP [WO 98/01480] into the final star macromolecule. Polymer
segments can comprise segments that are bio-degradable of are
formed from monomers prepared from biological sources.
[0183] As noted above the first formed ATRP macroinitiator can be
prepared by conducting a sequential ATRP (co)polymerization of
hydrophobic and hydrophilic monomers or precursors thereof or can
be prepared by other polymerization procedures that provide a
functional terminal atom or group that can be converted into an
ATRP initiator with a bifunctional molecule wherein one
functionality comprises a transferable atom or group and the other
functionality an atom or group that can react with the
functionality first present on the (co)polymer prepared by a
non-ATRP procedure. [WO 98/01480]
[0184] In aqueous solutions, the composition and molecular weight
of the outer shell of hydrophobes, or agents that participate in
molecular recognition, can be selected to induce self-assembly into
aggregates and act as physical crosslinkers. Above a certain
concentration, corresponding to the formation of a reversible three
dimensional network, the solutions will behave as physical gels
thereby modifying the rheology of the solution.
[0185] In one embodiment, the polymer compositions of the invention
have significantly lower critical concentration for network (gel)
formation compared to networks formed with block copolymers, graft
and stars with a low specific number of attached arms due to:
[0186] multi-arm structure (many transient junctions possible
between hydrophobic parts of the stars) [0187] very high molecular
weight of each star (5 thousand to 5 million or higher) allows high
swelling ratio of the molecules in solution [0188] molecular
organization on larger scales (>1 .mu.m)
[0189] Whereas the examples above and below describe the
preparation and use of block copolymers as arms with a well defined
transition from one segment to the adjoining segment a segmented
copolymer with a gradient in composition can also be utilized. The
presence of a gradient can be created by addition of a second
monomer prior to consumption of the first monomer and will affect
the volume fraction of monomer units present in the transition form
one domain to another. This would affect the shear responsiveness
of the formed star macromolecule.
[0190] Star macromolecules with narrow polydispersity comprising
arms with block copolymer segments can be formed with as few as 5
arms by selecting appropriate concentration of reagents,
crosslinker and reaction temperature.
[0191] Star macromolecules can be prepared in a miniemulsion or
reverse miniemulsion polymerization system. The first formed block
copolymers are used as reactive surfactants for star synthesis by
reaction with a selected crosslinker in miniemulsion.
EXAMPLES
TABLE-US-00001 [0192] Abbreviation Name Form Purity Commercial
Source St styrene liquid 99% Sigma Aldrich tBA tertiary-butyl
acrylate liquid 98% Sigma Aldrich AA acrylic acid (formed by
deprotection) NA NA NA HEA hydroxyethyl acrylate liquid 96% Sigma
Aldrich DEBMM diethyl 2-bromo-2-methylmalonate liquid 98% Sigma
Aldrich TPMA tris(2-pyridylmethyl)amine solid 95% ATRP Solutions
AIBN 2,2'-Azobis(2-methylpropionitrile) solid 98% Sigma Aldrich
Sn(EH).sub.2 tin(II) 2-ethylhexanoate liquid 95% Sigma Aldrich DVB
divinylbenzene liquid 80% Sigma Aldrich TFA trifluroacetic acid
liquid 99% Sigma Aldrich THF tetrahydrofuran liquid 99.9% Sigma
Aldrich NaOH sodium hydroxide solid 98% Sigma Aldrich EBiB Ethyl
.alpha.-bromoisobutyrate liquid 98% Sigma Aldrich Methylene
chloride liquid 99.6% Sigma Aldrich Acetonitrile liquid 99.8% Sigma
Aldrich NaCl Sodium chloride solid 99.7% Fisher Chemical DMAEMA
2-(dimethylamino)ethyl methacrylate PEGMA (polyethylene glycol)
methacrylate NIPAM N-isopropylacrylamide
Example 1
Synthesis, Purification and Properties of Star Thickening Agent
[0193] The initial examples of a star thickening agents with the
structure shown below in FIG. 1 as structure A, are star
macromolecules with PSt-b-PAA arms or PSt-b-P(HEA) arms.
Example 1
Preparation of a (PSt-b-PAA).sub.X Star Macromolecule
[0194] The simple four step procedure was developed for the
preparation of a poly(acrylic acid) based star macromolecule is
described in Scheme 3. 1 kg of the star macromolecule with
PSt-b-PtBA arms was prepared as follows.
[0195] STEP 1: Synthesis of a polystyrene macroinitiator using ICAR
ATRP. The reaction conditions are
St/DEBMM/CuBr.sub.2/TPMA/AIBN=50/1/0.002/0.003/0.05 in bulk at
T=60.degree. C., t=10.2 h. The reaction was run to .about.30%
conversion resulting in the molecular weight of the hydrophobic,
polystyrene segment=1600 which is equivalent to an average degree
of polymerization (DP) of 16.
[0196] The GPC trace obtained for the macroinitiator is shown in
FIG. 2.
[0197] STEP 2: Synthesis of polystyrene-b-poly(t-butyl acrylate)
segmented block copolymer macroinitiator. The reaction conditions
for the synthesis of PSt-b-PtBA macroinitiator arm are:
tBA/PSt/CuBr.sub.2/TPMA/Sn(EH).sub.2=200/1/0.01/0.06/0.008 in
anisole (0.5 volume eq. vs. tBA), T=55.degree. C., t=18.0 h. A
higher molecular weight precursor of the water soluble segment was
targeted to allow significant degree of swelling of the inner shell
of the final functional star macromolecule. The final molecular
weight of the poly(t-butyl acrylate) segment in the block copolymer
was .about.15,400 which is equivalent to a DP=120. The GPC curves
of the polystyrene macroinitiator and the formed block copolymer
macroinitiator is shown in FIG. 3 and clearly indicates that a
clean chain extension had occurred.
[0198] STEP 3: Synthesis of the (PSt-b-PtBA).sub.X Star
Macromolecule.
[0199] A multi-arm star macromolecule was prepared by conducting a
further chain extension reaction with the block copolymer
macroinitiator formed in step 2. The reaction was conducted with a
mole ratio of block copolymer to divinylbenzene of 1:12 in anisole.
The reaction conditions are:
DVB/PSt-b-PtBA/CuBr.sub.2/TPMA/Sn(EH).sub.2=12/1/0.02/0.06/0.1 in
anisole (38 volume eq. vs. DVB), T=80.degree. C., t=21.0 h). The
GPC curves and results of the star forming reaction are provided in
FIG. 4. It can be seen that a multi-arm star macromolecule with a
crosslinked core was formed. The GPC molecular weight of the star
was 102,700 with a PDI 1.29, which would indicate an average of six
arms but this is an underestimate of the actual number of arms
since the star molecule is a compact molecule. Indeed in this
situation the number of arms in the star molecule is close to
30.
[0200] The number of arms can be modified by conducting the core
forming reaction with a different ratio of crosslinking agent to
arm precursor or by running the reaction with a different
concentration of reagents.
[0201] STEP 4: Deprotection of the (PSt-b-PtBA).sub.X star
macromolecule to (PSt-b-PAA).sub.X star block copolymer to provide
water soluble poly(acrylic acid) segments in the multi-arm star
macromolecule. The PSt-b-PtBA arms of the star macromolecule were
transformed to PSt-b-PAA arms using a new procedure. Polymer was
dissolved in methylene chloride and trifluoroacetic acid to
deprotect tBu groups, the reaction was performed at room
temperature for 60.0 h. Then polymer was decanted and washed 3
times with acetonitrile. Polymer was then solubilized in THF and
precipitated into acetonitrile. The star macromolecule was dried in
vacuum oven for 3 days at 50.degree. C. The amount of polymer
obtained after purification was 550 g, which would correspond to
full conversion of PtBA to PAA.
Example 2
Properties of (PSt-b-PAA) Star Macromolecule as a Thickening
Agent
[0202] The thickening properties of the final star macromolecule
were investigated in aqueous solution. 100 mg of (PSt-b-PAA) star
macromolecule was dissolved in 0.5 ml of THF and transferred to 10
ml of water. Solution was then neutralized with 2 ml of basic water
(with NaOH). After few minutes of stirring gel was formed, see
image in FIG. 5.
[0203] The rheological properties of the multi-arm star built with
a longer poly(acrylic acid (PAA) hydrophilic internal core segment
and a short hydrophobic polystyrene (PSt) peripherial segment were
then investigated. The viscosity of aqueous solutions containing
different concentrations of the star macromolecule vs. shear rate
were measured; using a Brookfield LVDV-E, Spindle #31(or #34, #25)
at a T=25.degree. C., and the results are presented in FIG. 6. It
is clear that even very low concentrations of the star
macromolecule in water (<0.6 weight %) the apparent viscosity of
the sample is very high (in the range of 50,000 to 100,000
centipoise (cP)).
[0204] In comparison, leading thickening agents on the market for
personal care products (e.g. natural nonionic vegetable derived
liquid thickener Crothix Liquid by CRODA or synthetic acrylate
based copolymer DOW CORNING RM 2051) are used at the level of 2-5
weight % and only increase the viscosity of a water based solution
up to 5,000-20,000 cP.
[0205] FIG. 7 presences the viscosity of aqueous solution of a
(PSt-b-PAA) star macromolecule vs. concentration. The measurement
was conducted on a Brookfield LVDV-E with spindle #31(or #34, #25)
at a temperature=25.degree. C. and rate=1 RPM. It can be seen that
for this particular star macromolecule 0.3 weight % concentration
of star macromolecule in water is a minimum amount for gel
formation and that higher concentrations significantly increase the
viscosity of the resulting solution.
[0206] Tests indicated that the thickening agent provided
formulations that exhibited a lack of tackiness, a very pleasant
feel on the skin.
Example 3
Properties of (PSt-b-PAA) Star Macromolecule as Thickening Agents
in Harsh Environments
[0207] The thickening properties of the final star macromolecule
were investigated in aqueous solution in the presence of an
oxidizing agent and at high pH. FIG. 8 presents the viscosity of an
aqueous solution of (PSt-b-PAA) star macromolecule and the
viscosity of water/windex (1/1 v/v) solution of (PSt-b-PAA) star
macromolecule and FIG. 9 presents the results obtained with
Carbopol EDT 2020 in the same media. The pH of the aqueous solution
was 6-7 while for the water/Windex solution pH=9-10. (Measurement
of viscosity was conducted using a Brookfield LVDV-E, Spindle #31
(or #34, #25), T=25.degree. C.) It can be seen that viscosity of
water/windex solution is higher than that of water solution. The
performance of (PSt-b-PAA) star macromolecule as thickening agent
is not diminished in this harsh environment presented by the
windex/water solution with a pH=9-10 resulting from the presence of
high amount of ammonia-D. In comparison, the thickening properties
of the leading thickener on the market, Carbopol EDT 2020, were
decreased in similar conditions and FIG. 9 shows that the viscosity
of water/windex solution is lower than that of pure aqueous
solution.
[0208] It is envisioned that the poor performance of Carbopol vs.
(PSt-b-PAA) star macromolecule as thickening agent in water/Windex
solution is a consequence of the high amount of ester bonds in its
structure which can interact with the ionic species present in such
harsh environment or can be even degraded. On the other side
(PSt-b-PAA) star macromolecule has only C--C bonds, which make this
thickening agent stable in water/Windex solution and overall
thickening performance is not decreased.
Example 4
Properties of (PSt-b-PAA) Star Macromolecule Vs. (PAA) Star
Macromolecule as Thickening Agents
[0209] A (PAA) star macromolecule was synthesized in order to
compare its properties to those determined for the (PSt-b-PAA) star
macromolecule. Synthesis of (PAA) star was performed in similar way
as for synthesis of (PSt-b-PAA) star macromolecule but starting
with pure PtBA arms.
[0210] The final (PAA) star had similar molecular weight, number of
arms and molecular weight distribution to the (PSt-b-PAA) star
macromolecule, FIG. 10. The only one difference between two star
macromolecules is the outer shell which comprises of PSt with
degree of polymerization 16 in (PSt-b-PAA) star macromolecule
whereas this star macromolecule posses pure PAA homo-polymeric
arms. FIG. 11 presents the viscosity of aqueous solutions of
(PSt-b-PAA) star and (PAA) star macromolecules. The measurement was
conducted using a Brookfield LVDV-E fitted with a #31 spindle at a
temperature=25.degree. C. and pH=7. It can be seen that viscosity
of star macromolecule with a hydrophobic outer shell has very
strong thickening properties, where the pure (PAA) star has low
thickening effect on water.
[0211] Therefore one can conclude that in order to thicken aqueous
based media the proposed multi-arm star macromolecules have to have
a blocky structure, with a hydrophilic inner shell and a
hydrophobic outer shell. Without wishing to be limited by a
proposed mechanism we believe these results in aqueous media can be
explained by the induced self-assembly of the hydrophobic segments
into aggregates, the hydrophobes act as "junctions" between
aggregates, and above a certain concentration, a three-dimensional
reversible physical network is formed with a behavior similar to
conventional gels.
Example 5
(PSt-b-PAA) Star Macromolecule as Thickening and Emulsifying
Agent
[0212] Due to its very well-defined structure, (PSt-b-PAA)
multi-arm star macromolecule may act not only as a thickening agent
but also as efficient emulsifying agent. FIG. 12 presents images
demonstrating the emulsifying properties of (PSt-b-PAA) star
macromolecule. First photograph shows mixture of water with 2
volume % of pure lemon oil. After vigorous mixing, water and oil
quickly separated into two phases. The second photograph presents
water with 2 volume % of lemon oil and 0.6 weight % of thickening
agent. After vigorous mixing, the phase separation did not occur
and thicken properties did not decrease. Solutions were shaken for
1 min and photographs were taken 2 h after mixing.
[0213] Its hydrophobic core (as well as hydrophobic outer shell)
may act as a storage place for small organic molecules (e.g.
vitamins, fragrances, sunblock agents, etc.). This provides for the
possibility for delivery of functional organic molecules, e.g.
fragrance for slow release or UV absorbing molecules in sunscreens
to any part of the body in a pleasant feeling emulsion.
[0214] In order to provide an equivalent response for non-polar
media the phylicity of the inner and outer shells would have to be
reversed.
Example 6
Mikto-Arm Star Macromolecules
[0215] A multi-arm star macromolecule was synthesized. The
procedures for forming the arms PSt-b-PtBA and PtBA were similar to
that described in Example 1. Next, two different arms were
crosslinked together to form a star macromolecule. Reaction
conditions for core forming crosslinking reaction:
DVB/[PSt-b-PtBA/PtBA]/CuBr2/TPMA/Sn(EH)2=17/1/0.02/0.06/0.2 in
anisole (38 volume eq. vs. DVB), (1667 ppm of Cu) T=95.degree. C.,
t=53.0 h, PSt-b-PtBA/PtBA=1/4. Next, PtBA was transformed to PAA by
deprotection with acid as described in Step 4 in Example 1.
[0216] FIG. 13 shows the GPC curves of the arms and the formed
mikto-arm star macromolecule before and after purification by
precipitation. Schematic 13B shows a representation of such a
mikto-arm star macromolecule.
[0217] Synthesis of stars with lower amounts of the outer PSt block
was successfully performed. Two stars were synthesized, one with
50% and one with 20% of PSt-b-PAA arms and 50% and 80% pure PAA
arms (WJ-08-006-234 and WJ-06-235) by the procedures detailed
above. Studies show that these star macromolecules can be dispersed
directly in warm water. Thickening properties of these two new
stars were as good as first exemplary star with 100% of PSt-b-PAA
arms.
[0218] Stars with different outer hydrophobic shells can be
prepared. One example that provides an outer shell which exhibits a
Tg below use temperature is a star prepared with a PnBA outer
shell.
[0219] Another approach which can reduce the cost of the preparing
an outer hydrophobic shell is conversion of commercially available
.alpha.-olefins to an ATRP initiator by reaction with a
halo-alky(meth)acrylylhalide.
Example 7
Stars with Different Hydrophobic Segments
[0220] One parameter which may significantly change viscosity of
thickening agent as well as its interaction with surfactant in
shampoo formulations is the type of hydrophobic unit capped at the
peripheral end of a fraction of the arms of the star macromolecule.
Two additional stars were synthesized in order to compare to
(PSt.sub.16-PAA.sub.120).sub.X (before deprotection:
M.sub.n,app=102,700 g/mol, PDI=1.29) star macromolecule.
[0221] These stars include:
[0222] A) C.sub.18-PAA.sub.146).sub.X: M.sub.n,app=95,600 g/mol,
PDI=1.48,
[0223] B) C.sub.12-PAA.sub.134).sub.X: M.sub.n,app=113,900 g/mol,
PDI=1.53,
[0224] Each star was prepared in three steps: [0225] i) preparation
of PtBA arm, [0226] ii) crosslinking arms into star macromolecule,
[0227] iii) deprotection of tBu groups. All of the stars had
relatively low PDI with low amount of unreacted arms (<15 wt
%).
[0228] A new PtBA macroinitiator was prepared from an initiator
containing a linear C.sub.18 alkyl chain for preparation of the
(C.sub.18-PAA.sub.146).sub.X star. The synthesis of this arm
precursor C.sub.18-PtBA-Br was accomplished using ARGET ATRP of tBA
using C.sub.18 alkyl chain functionalized EBiB. The conditions and
properties of synthesized polymer are shown in Table 1.
TABLE-US-00002 TABLE 1 Experimental conditions and properties of
PtBA prepared by ARGET ATRP..sup.a Molar ratios Cu Time Conv. Entry
tBA I CuBr.sub.2 L RA [ppm] (min) (%) M.sub.n,theo.sup.b
M.sub.n,GPC M.sub.w/M.sub.n 08-006-160 300 1 0.015 0.06 0.1 50 1380
47 18200 19700 1.19 TPMA .sup.aI = C.sub.18-EBiB, L = Ligand, RA =
reducing agent = Sn(EH).sub.2; [tBA].sub.0 = 4.67M; T = 60.degree.
C., in anisole (0.5 volume equivalent vs. monomer); .sup.bM.sub.n,
theo = ([M].sub.0/[C.sub.18-EBiB].sub.0) .times. conversion
[0229] This macroinitiator was than crosslinked using DVB into a
star macromolecule. After deprotection of tBu groups by stirring
the reaction for 3 days in the presence of TFA resulting in
transformation to PAA units star was precipitated from
CH.sub.2Cl.sub.2. The viscosity of resulting (C.sub.18-PAA).sub.X
star and the (C.sub.12-PAA).sub.X star can be compared to
(PSt-b-PAA).sub.X in water and shampoo formulations.
Example 8
Stars with an Inner P(HEA) Shell
[0230] P(HEA) star macromolecules that comprise water soluble
non-ionizable hydrophilic segments selected to make the star
macromolecules compatible with solutions further comprising
dissolved/dispersed salts that are additionally stable over a broad
range of pH.
[0231] The PSt-b-PHEA arm precursor was prepared using ICAR ATRP.
Conditions for the polymerizations and characterization of the
resulting polymer are shown in Table 2. Polymerization was well
controlled and well-defined block copolymer was prepared with
relatively low (PDI=1.26 and 1.20). This is the first example of
successful ICAR ATRP for acrylate type monomer. PSt-b-PHEA arm
precursor was purified by precipitation into ethyl ether and dried
under vacuum over two days at 50.degree. C.
TABLE-US-00003 TABLE 2 Experimental conditions and properties of
PSt-b-PHEA prepared by ICAR ATRP..sup.a Molar ratios Cu Time Conv.
Entry HEA I CuBr.sub.2 L RA [ppm] (min) (%) M.sub.n,theo.sup.b
M.sub.n,GPC M.sub.w/M.sub.n 08-006- 200 1 0.04 0.04 0.1 200 1200 63
16100 30400 1.26 155 TPMA 08-006- 300 1 0.05 0.05 0.05 167 1230 54
20300 42300 1.20 158 TPMA .sup.aI = PSt (08-006-29, M.sub.n = 1600
g/mol, PDI = 1.20), L = Ligand, RA = reducing agent = AIBN;
[HEA].sub.0 = 5.44M; T = 65.degree. C., in DMF (0.7 volume
equivalent vs. monomer); .sup.bM.sub.n, theo =
([M].sub.0/[PSt].sub.0) .times. conversion.
[0232] Different crosslinking agents were investigated, including
DVB and in run 08-006-159 di(ethylene glycol) diacrylate (DEGlyDA)
and in run 08-006-161 DEGlyDA with small amount of HEA monomer. The
reaction was not fully controlled when conversion of the added
divinyl crosslinker was driven to high conversion as a consequence
of star-star core coupling reactions resulted in gel formation.
However at lower conversion of the crosslinker and under more
dilute conditions star macromolecules were formed.
Example 9
Preparation of a
(PSt.sub.15-b-PAA.sub.290/PAA.sub.150).sub..apprxeq.30 Miktoarm
Star Macromolecule (Referenced Herein as Advantomer)
[0233] The simple four step procedure was developed for the
preparation of a poly(acrylic acid) based miktoarm star
macromolecule and is described in Scheme 4. 1 kg of the miktoarm
star macromolecule with PSt-b-PAA and PAA arms (molar ratio of arms
4/1) was prepared as follows.
##STR00004##
[0234] STEP 1: Synthesis of a Polystyrene Macroinitiator (PSt)
Having 15 DP
[0235] A polystyrene macroinitiator was formed using ICAR ATRP by
introducing the following components into the reaction vessel at
the following molar ratio:
St/DEBMM/CuBr.sub.2/TPMA/AIBN=50/1/0.002/0.003/0.05 in bulk at
T=60.degree. C., t=10.2 h. The reaction was run to .about.30%
conversion. The resulting reaction product was purified to obtain
the PSt in powder form. A portion of the PSt powder was dissolved
in THF and passed through the GPC column. The GPC trace obtained
for the macroinitiator is shown in FIG. 2. The measured molecular
weight of the hydrophobic, polystyrene segment=1600 which is
equivalent to an average degree of polymerization (DP) of about
15-16 and the PDI was measured to be 1.24.
[0236] STEP 2: One-Pot Synthesis of Polystyrene-b-Poly(t-Butyl
Acrylate) and Poly(t-Butyl Acrylate) Macroinitiator
[0237] The following components were introduced into the reaction
vessel in the following molar ratio: tBA/PSt (from
step1)/CuBr.sub.2/TPMA/Sn(EH).sub.2=200/0.2/0.01/0.06/0.1, in
anisole (0.5 volume eq. vs. tBA), T=55.degree. C. About 2.0 hours
after the reaction was initiated, the conversion of the tBA reached
about 6% and a portion of the PSt-b-PtBA was recovered and measured
by GPC with the following results M.sub.n=19,800 g/mol; PDI=1.16.
It was determined that the following PSt.sub.15-b-PtBA.sub.140
copolymeric block was obtained. Then, 0.8 molar ratio amount,
relative to the initially introduced components, of Ethyl
2-bromoisobutyrate (EBiB) was injected into the polymerization
mixture. The reaction was continued and stopped after about 19.8 h.
The reaction product was purified and the product was analyzed by
GPC. Based on the GPC measured values the final molecular weight of
the product was determined to be poly(t-butyl acrylate) segment in
the block copolymer was .about.37,200 g/mol
(PSt.sub.15-b-PtBA.sub.290) and the molecular weight of
poly(t-butyl acrylate) initiated from EBiB was 19,200 g/mol which
is equivalent to a DP=150. The overall molecular weight of mixture
of arms resulted in M.sub.n=20,800 g/mol and PDI=1.27. The GPC
curves of the polystyrene macroinitiator and the mixture of formed
block copolymer arms PSt.sub.15-b-PtBA.sub.290 and poly(t-butyl
acrylate) arms PtBA.sub.150 are shown in FIG. 23. The signal from
block copolymer is overlapping with signal from homopolymer but
this result clearly indicates that a clean chain extension from PSt
had occurred.
[0238] STEP 3: Synthesis of the (PSt-b-PtBA/PtBA).sub..apprxeq.30
Miktoarm Star Macromolecule.
[0239] A mikto multi-arm star macromolecule was prepared by
conducting a further chain extension reaction with the block
copolymer and homopolymer macroinitiators formed in step 2. The
reaction was conducted with a mole ratio of macroinitiators to
divinylbenzene of 1:16 in anisole. The following components were
introduced into the reaction vessel in the following molar ratio:
DVB/[PSt-b-PtBA/PtBA] (from step
2)/CuBr.sub.2/TPMA/Sn(EH).sub.2=16/1/0.02/0.07/0.15 in anisole (38
volume eq. vs. DVB), T=95.degree. C., t=20.6 h. The reaction
product was purified and the product was analyzed by GPC. The GPC
curves and results of the star forming reaction are provided in
FIG. 24. It can be seen that a multi-arm star macromolecule with a
crosslinked core was formed. The GPC apparent molecular weight of
the star was 109,400 with a PDI 1.52, which would indicate an
average of six arms but this is an underestimate of the actual
number of arms since the star molecule is a compact molecule.
Indeed in this situation, the number of arms in the star molecule
is close to 30.
[0240] The number of arms can be modified by conducting the core
forming reaction with a different ratio of crosslinking agent to
arm precursor or by running the reaction with a different
concentration of reagents.
[0241] STEP 4: Deprotection of the (PSt-b-PtBA/PtBA) to
(PSt-b-PAA/PAA)
[0242] Deprotection of the (PSt-b-PtBA/PtBA).sub..apprxeq.30 star
macromolecule to (PSt-b-PAA/PAA).sub..apprxeq.30 star block
copolymer to provide water soluble poly(acrylic acid) segments in
the mikto multi-arm star macromolecule. The PSt-b-PtBA/PtBA arms of
the miktoarm star macromolecule were transformed to PSt-b-PAA/PAA
arms with the following procedure. Polymer was dissolved in
methylene chloride and trifluoroacetic acid to deprotect tBu
groups, the reaction was performed at room temperature for 60.0 h.
Then polymer was decanted and washed 3 times with acetonitrile.
Polymer was then solubilized in THF and precipitated into
acetonitrile. The star macromolecule was dried in vacuum oven for 3
days at 50.degree. C. The amount of polymer obtained after
purification was 550 g, which would correspond to full conversion
of PtBA to PAA.
Test Results Table--comparing the star macromolecule formed in
Example 9 (Advantomer) against commerically available thickening
agent, Carbopol ETD 2020.
TABLE-US-00004 Advantomer (as formed in Properties Example 9)
Carbopol ETD 2020 Dynamic Viscosity 25,830 cP @ 48,000 cP @ 0.2 wt
% (@1 rpm) 0.2 wt % Salt-Induced Break Value 87.8% @ 0.7 wt % 52.4%
@ 0.4 wt % pH-Induced Break Value 99.3% @ 0.4 wt % 12.6% @ 0.2 wt %
Sheer-Thinning Value 32.7@ 0.2 wt % 12.9@ 0.2 wt % Strong Gel Yes
Yes Emulsion Value >12 hours <5 min. HLM >0.96 N/A
Test Procedures
[0243] Sample Preparation
[0244] Aqueous gel compositions were prepared at various
concentrations (e.g., 0.2 wt. %, 0.25 wt %, 0.4 wt. % 0.6 wt. %,
0.7 wt. % and 1.0 wt. %) by heating and stirring, as necessary
(e.g., vigorously mixing at a temperature of about 60.degree. C.)
the sample material (e.g., a star macromolecular powder or Carbopol
ETD 2020) into water pH adjusted, as necessary, (e.g., a pH of
about 7.5 with addition of sodium hydroxide) to obtain a homogenous
mixture.
[0245] Dynamic Viscosity & Shear-Thinning Test Procedure
[0246] A portion of the sample preparation was introduced into a
Brookfield LVDV-E Digital Viscometer, using spindle #31 for mixing,
at STP, over a wide range of rates (e.g, 0.3-100 rpm) and the shear
rate and viscosity was recorded. Viscosity measurements were taken
in the following sequence without stopping the instrument, 0.3,
0.5, 1, 2, 5, 10, 20, 30, 50, and 100 rpm. The dynamic viscosity
was determined as the viscosity in centipoise (cP) at 0.3 rpm. A
shear-thinning value was determined by dividing the dynamic
viscosity value at 0.3 rpm by the dynamic viscosity value at 20
rpm.
TABLE-US-00005 Viscosity [cP] Shear Rate Advantomer Carbopol
[s.sup.-1] rpm 0.2 wt % 0.2 wt % 0.102 0.3 67100 85000 0.17 0.5
46980 65600 0.34 1 25830 48000 0.68 2 13880 23300 1.7 5 6580 15800
3.4 10 3620 10400 6.8 20 2050 6600 10.2 30 1480 4800 17 50 1000
3300 34 100 690 2250
Salt-Induced Break Test Procedure
[0247] A portion of the sample preparation was introduced into 20
ml glass scintillation vial. A measured portion of NaCl was added
into the vial (e.g., 0.05 wt. % relative to the total weight of the
sample in the vial. After the NaCl addition was complete, the vial
was closed and shaken for 10 min. Then, the viscosity of the sample
was measured in accordance with the Dynamic Viscosity &
Shear-Thinning Test Procedure, above, and the dynamic viscosity at
1 rpm was recorded. This procedure was repeated for differing
concentrations of NaCl. The results are presented in FIGS. 18 &
22. The salt-induced break value, in percent, is determined by the
following equation:
Initial Dynamic Viscosity (0% NaCl)-Dynamic Viscosity (0.05 wt. %
NaCl)/Initial Dynamic Viscosity (0% NaCl).times.100%.
pH Efficiency Range Test Procedure
[0248] An aqueous gel composition at 0.4 wt. % was prepared for the
star macromolecule of Example 9, at a starting pH of around 5 and a
separate aqueous gel composition at 0.2 wt. % aqueous gel
composition of Carbopol ETD 2020, at a starting pH of around 3, was
prepared by mixing and heating, as necessary (e.g., vigorous mixing
at a temperature of about 60.degree. C.). Then, the viscosity of
the sample was measured in accordance with the Dynamic Viscosity
& Shear-Thinning Test Procedure, above, and the dynamic
viscosity at 1 rpm was recorded. This procedure was repeated for
differing pH values, adjusted by addition of sodium hydroxide. The
results are presented in FIG. 19. The ph-induced break value, in
percent, is determined by the following equation:
Dynamic Viscosity (at 1 rpm) at pH 7.5-Dynamic Viscosity (at 1 rpm)
at pH 5/Dynamic Viscosity (at 1 rpm) at pH 7.5.times.100%.
Emulsion Test Procedure
[0249] 340 mL of water was added to a 500 ml beaker and stirred
vigorously with an overhead stirrer. 1.6 g of the material to be
tested for emulsifying effect was added and heated to 8.degree. C.
The solution was pH adjusted with 400 mg of NaOH and stirring
continued until a homogeneous gel was obtained. 60 ml sunflower oil
was added while vigorous stirring was continued with an overhead
stirrer at 80 C for 10 min or until homogenous emulsion is
obtained. The mixture was allowed to cool to room temperature. Once
the system cools to room temperature start timer. The emulsion
value is the time, in minutes, it takes for the system to form two
visible layers (phase separation).
Strong Gel Test Procedure
[0250] 10 ml portion of the sample preparation material was
introduced into a 20 ml glass scintillation vial. After the
transfer was complete, the vial was placed on a surface and
remained undisturbed for about 20 minutes at STP. The vial was then
gently inverted (turned-upside down) and placed on the surface and
a timer started. If after 5 minutes, there is no visible flow then
the sample is said to be a strong gel.
[0251] Hydrophilic-Lipophilic (HLB) Arm/Segment Calculation
HLB=20*Mh/M
where Mh is the molecular mass of the hydrophilic portion of the
polymeric arm or segment, and M is the molecular mass of the whole
polymeric arm or segment.
[0252] Hydrophilic-Lipophilic Macromolecule Calculation
HLM = divided by 0.3 M W core + n = 1 n - m M W n ##EQU00001##
where [0253] MW.sub.n is the molecular weight for the respective
arm, [0254] HLB.sub.n is the HLB, as calculated from the HLB arm
calculation, for the respective arm, and [0255] MW.sub.core is the
molecular weight for the core, and [0256] M is the total number of
arms.
[0257] The disclosed star macromolecules can find utility in a
spectrum of applications including, but not limited to; personal
care: including shampoos/conditioners, lotions, serums, creams,
solids, gelly, cosmetics: including mascara, blush, lip stick,
powders, perfumes and home care: including cleaners for windows,
household and work surfaces, toilet areas, laundry, and in dish and
dishwasher applications.
* * * * *