U.S. patent application number 16/291828 was filed with the patent office on 2019-10-10 for amino-substituted polysiloxanes combined with polymerizable and unpolymerizable organic acids.
The applicant listed for this patent is Georgetown University. Invention is credited to Yong He, Ajaya M.V. Mallya, Richard G. Weiss, Tao Yu.
Application Number | 20190309132 16/291828 |
Document ID | / |
Family ID | 51210083 |
Filed Date | 2019-10-10 |
View All Diagrams
United States Patent
Application |
20190309132 |
Kind Code |
A1 |
Weiss; Richard G. ; et
al. |
October 10, 2019 |
AMINO-SUBSTITUTED POLYSILOXANES COMBINED WITH POLYMERIZABLE AND
UNPOLYMERIZABLE ORGANIC ACIDS
Abstract
Provided is a composition comprising (i) a polysiloxane
comprising a plurality of pendant amines and (ii) an acid. Also
provided is a composition comprising (i) a polysiloxane comprising
a plurality of pendant acids and (ii) an amine. The compositions
are useful inter alia for chemical or oil spill cleanup, drug
delivery systems, transparent films, adhesives, binding agents,
conductors, membranes, cross-linking agents, or opticoelectronic
applications. Also provided are methods for making the compositions
of the invention, as well as a battery and a composition for
controlled release of a compound, each comprising a composition of
the invention.
Inventors: |
Weiss; Richard G.;
(Bethesda, MD) ; Mallya; Ajaya M.V.; (Washington,
DC) ; He; Yong; (Arlington, VA) ; Yu; Tao;
(Arlington, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Georgetown University |
Washington |
DC |
US |
|
|
Family ID: |
51210083 |
Appl. No.: |
16/291828 |
Filed: |
March 4, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14761680 |
Jul 17, 2015 |
10221283 |
|
|
PCT/US2014/012000 |
Jan 17, 2014 |
|
|
|
16291828 |
|
|
|
|
61904549 |
Nov 15, 2013 |
|
|
|
61754274 |
Jan 18, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08K 5/09 20130101; C09J
183/06 20130101; C08K 5/09 20130101; C08G 77/38 20130101; C09J
183/08 20130101; C08K 5/092 20130101; H01M 4/602 20130101; C08G
77/392 20130101; C08K 5/092 20130101; C08G 77/388 20130101; A61K
47/34 20130101; H01M 10/052 20130101; C08G 77/20 20130101; C08G
77/26 20130101; C08L 83/08 20130101; C08L 83/08 20130101 |
International
Class: |
C08G 77/38 20060101
C08G077/38; H01M 4/60 20060101 H01M004/60; C08G 77/388 20060101
C08G077/388; A61K 47/34 20060101 A61K047/34; C08G 77/392 20060101
C08G077/392 |
Claims
1-14. (canceled)
15. A composition, comprising a polysiloxane comprising a plurality
of pendant acids selected from the group consisting of carboxylic
acids and sulfonic acids; and an amine.
16. The composition of claim 15, wherein each of the plurality of
pendant acids is a carboxylic acid.
17. The composition of claim 15, wherein each of the plurality of
pendant acids is a carboxylic acid attached to the polysiloxane via
an alkyl chain optionally substituted with one or more alkyl,
haloalkyl, halide, aryl, or aralkyl groups.
18. The composition of claim 15, wherein each of the plurality of
pendant acids is a sulfonic acid.
19. The composition of claim 15, wherein each of the plurality of
pendant acids is a sulfonic acid attached to the polysiloxane via
an alkyl chain optionally substituted with one or more alkyl,
haloalkyl, halide, aryl, or aralkyl groups.
20. The composition of claim 15, wherein the amine is a primary
amine.
21. The composition of claim 15, wherein the amine is a secondary
amine.
22. The composition of claim 15, wherein the amine is a tertiary
amine.
23. The composition of claim 15, wherein the amine is a quaternary
amine.
24. The composition of claim 15, wherein the amine is a diamine or
amidine.
25. The composition of claim 15, wherein the amine is substituted
with one, two, or three alkyl, alkenyl, alkynyl, cycloalkyl,
aromatic, or alkoxy groups.
26. The composition of claim 15, wherein the amine is acyclic.
27. (canceled)
28. A method of preparing the composition according to claim 15,
comprising the step of combining a polysiloxane comprising a
plurality of pendant acids selected from the group consisting of
carboxylic acids and sulfonic acids; and an amine.
29. The method of claim 28, further comprising the step of
irradiating the composition.
30. A battery, comprising a composition of claim 15.
31. The battery of claim 30, further comprising a plurality of
lithium ions.
32. A composition for controlled release of a compound, comprising
the composition of claim 15; and the compound.
33. The composition of claim 32, wherein the compound is an active
pharmaceutical ingredient.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/761,680, filed Jul. 17, 2015, now U.S. Pat.
No. 10,221,283, which is a 35 U.S.C. .sctn. 371 filing of
International Patent Application No. PCT/US2014/012000, filed Jan.
17, 2014, which claims the benefit of priority to U.S. Provisional
Patent Application Nos. 61/754,274, filed Jan. 18, 2013, and
61/904,549, filed Nov. 15, 2013, the entire contents of which are
incorporated herein by reference.
BACKGROUND
[0002] Polysiloxanes have a myriad of uses in daily life, and many
substituted polysiloxanes have allowed the list of uses to become
even larger. Amino groups attached to the side chains of
polysiloxane backbones offer an attractive platform from which
subtle chemical changes can be made easily, leading to large
changes in the bulk properties of the materials. Simple alterations
of amino-substituted polysiloxanes have been exploited to produce
new materials. For example, addition of an uncharged triatomic
molecule, such as CO.sub.2 or CS.sub.2, can create ionic centers
within the polymer matrixes that have a profound effect on the
viscosity, adhesive, and swelling properties of a polysiloxane.
Depending on the nature of the triatomic molecule added, the
post-addition treatment, the percent of monomers in the
polysiloxane with an amino functionality, and the type of amino
group, the materials can be transformed from the free-flowing,
slippery liquids to strong (reversible) adhesives and very viscous
syrups, rubbery materials, or gels, some of which are able to
imbibe selectively large amounts of low polarity solvents.
[0003] The effects of other simple additives which are capable of
creating ion pairs within the polysiloxanes on the polymer
properties remain a potential source of cost-effective and useful
materials.
SUMMARY OF THE INVENTION
[0004] An aspect of the present invention relates to polysiloxane
materials containing a basic functional group (e.g., amine or other
group capable of accepting a proton) combined with an acid to form
materials with useful properties (e.g., as transparent films,
adhesives, binding agents, conductors, membranes, or
controlled-release systems). In certain embodiments, the acid is a
mono-acid (e.g., acetic acid). In certain embodiments, the acid is
a di-acid (e.g., succinic acid). In certain embodiments, the acid
is a tri-acid. In certain embodiments, the acid contains an
aromatic group.
[0005] An aspect of the present invention relates to polysiloxane
materials containing an acidic functional group (e.g., carboxylic
acid or other group capable of donating a proton) combined with a
base to form materials with useful properties (e.g., as transparent
films, adhesives, binding agents, conductors, membranes, or
controlled-release systems). In certain embodiments, the base is
mono-basic (e.g., butyl amine, di(isopropyl)amine, or
triethylamine). In certain embodiments, the base is di-basic (e.g.,
ethylene diamine). In certain embodiments, the base is tri-basic.
In certain embodiments, the base contains an aromatic group (e.g.,
aniline).
[0006] The changes in rheological, adhesive, and swelling
properties that occur when a series of mono-carboxylic acids or
di-carboxylic acids are added to 6-7PSil, a polysiloxane in which
6-7% of the side groups contain a primary amine functionality, give
rise to materials useful as polymer networks for chemical or oil
spill cleanup, drug delivery systems, transparent films, adhesives,
binding agents, conductors, membranes, cross-linking agents, or
opticoelectronic applications. Those changes are correlated with
(especially) the structures of the acids. In addition, described
herein are materials made from in situ photo-polymerization of
unsaturated carboxylic acids that were added to the polysiloxane.
The results demonstrate that drastic changes effected by such
additions (or polymerizations) lead to materials with drastically
different properties than those of the parent polysiloxane.
Clearly, the materials may be useful in a variety of new
applications, and the protocols described here can be applied
directly to other amino-substituted polymers, including those which
are not polysiloxanes.
[0007] Polysiloxane ammonium salts have wide-ranging utility
primarily based on the unique character of silicon-containing
polymers (e.g., stability, low water solubility) and their
adaptability to various technical fields. Polysiloxanes exhibit low
surface tension, high flexibility, excellent stability to heating,
and resistance to oxidation and aging. However, the high
malleability and relatively low viscosity of polysiloxane can be
disadvantageous because they can't be made into fibers and
immobilized films without significant structural modifications,
such as crosslinking. Crosslinking systems have been designed
consisting of the polysiloxane amine and CO.sub.2 or CS.sub.2. At
the same time, it is widely known that amines form ammonium salts
when combined with an acid. So polysiloxane ammonium salt could be
easily produced with polysiloxane amine, but it would exhibit
higher hydrophilicity than polysiloxane amine, which may lead to
different aggregation, solubility, rheology or swelling
properties.
[0008] In the present invention, ammoniumpolysiloxane networks with
acids such as carboxylates are produced from aminopolysiloxane such
as 6-7PSil or D.sub.2EDA (see structure in Scheme 1) and different
mono-acids or di-acids. Ionic crosslinking could be realized
through the salt formation reaction of the two carboxylic groups of
a diacid compound, or even through electrostatic interactions when
a monocarboxylic acid was employed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts vertically offset IR spectra of acetic acid
(bottom), D.sub.2EDA (middle), and ammonium acetate of D.sub.2EDA
(top, with one equivalent of acetic acid), synthesized as described
for 6-7PSil.
[0010] FIG. 2 depicts vertically offset .sup.1H NMR spectra of
6-7PSil without (1), and with one molar equivalent of
trifluoroacetic acid in CDCl.sub.3 after 0.5 h at 25.degree. C. (2)
another 0.5 h at 50.degree. C. (3) and 1.5 h at 50.degree. C.
(4).
[0011] FIG. 3 depicts average viscosities over 0.1-100 Pa shear
stress of 6-7PSil and its ammonium carboxylate salts.
[0012] FIG. 4 depicts moduli of 6-7PSil and its ammonium
carboxylates at 1.2% strain and 1 Hz frequency.
[0013] FIG. 5A depicts moduli versus strain at 1 Hz frequency.
[0014] FIG. 5B depicts frequency sweep at 1% strain of PD2.
[0015] FIG. 6 tabulates maximum normal force measurements to break
6-7PSil ammonium carboxylate films between steel plates.
[0016] FIG. 7 depicts maximum shear force necessary to move films
of 6-7PSil ammonium salts
[0017] FIG. 8 depicts viscosity of 6-7PSil ammonium acrylate (PMAA)
before (bottom curve) and after (upper curve) irradiation.
[0018] FIG. 9 depicts moduli (1 Hz frequency) of 6-7PSil ammonium
acrylate (PMAA) before (lower two curves) and after (upper two
curves) irradiation (G', square; G'', circle).
[0019] FIG. 10 depicts shear force versus extension of a 6-7PSil
ammonium acrylate (PMAA) film between glass plates before (lower
curve) and after (upper curve) irradiation.
[0020] FIG. 11 depicts vertically offset 1H NMR spectra of 6-7PSil
without (a) and with 0.5 (b), 0.75 (c) and 1.0 (d) molar
equivalents of benzoic acid in CDCl.sub.3.
[0021] FIG. 12 depicts viscosities versus shear stress of 6-7PSil
ammonium carboxylates.
[0022] FIG. 13 depicts moduli of PM1 versus strain at 1 Hz
frequency. See Table 1 for definitions of various acronyms used
throughout the specification and Figures.
[0023] FIG. 14 depicts moduli of PM2 versus strain at 1 Hz
frequency.
[0024] FIG. 15 depicts moduli of PMPh versus strain at 1 Hz
frequency.
[0025] FIG. 16 depicts moduli of PMCF3 versus strain at 1 Hz
frequency.
[0026] FIG. 17 depicts moduli of PDA7 versus strain at 1 Hz
frequency.
[0027] FIG. 18 depicts moduli of PD4 versus strain at 1 Hz
frequency.
[0028] FIG. 19 depicts moduli of PD3 versus strain at 1 Hz
frequency.
[0029] FIG. 20 depicts moduli of PD1 versus strain at 1 Hz
frequency.
[0030] FIG. 21 depicts moduli of PD0 versus strain at 1 Hz
frequency.
[0031] FIG. 22 depicts a frequency sweep of PMPh at 1% strain.
[0032] FIG. 23 depicts a frequency sweep of PMCF3 at 1% strain.
[0033] FIG. 24 depicts a frequency sweep of PD7 at 1% strain.
[0034] FIG. 25 depicts a frequency sweep of PD4 at 1% strain.
[0035] FIG. 26 depicts a frequency sweep of PD3 at 1% strain.
[0036] FIG. 27 depicts a frequency sweep of PD1 at 1% strain.
[0037] FIG. 28 depicts a frequency sweep of PD0 at 1% strain.
[0038] FIG. 29 depicts viscosity (top curve) and G'' (bottom curve;
at 1.2% strain and 1 Hz frequency) of PMPh as a function of
different amounts of added benzoic acid.
[0039] FIG. 30 depicts viscosity (top curve) and G'' (bottom curve,
at 1.2% strain and 1 Hz frequency) of PM1 as a function of
different amounts of added acetic acid.
[0040] FIG. 31 depicts viscosity of PM2 with 3 wt % Darocur 1173
before (squares) and after (circles) irradiation.
[0041] FIG. 32 depicts moduli of PM2 with 3 wt % Darocur 1173 (at 1
Hz frequency) before and after irradiation.
[0042] FIG. 33 depicts normal force from extensional rheology of
PM2 with 3 wt % Darocur 1173 before (upper curve) and after (lower
curve) irradiation.
[0043] FIG. 34 depicts the .sup.1H NMR spectrum of 6-7PSil
vinylbenzoate in CDCl.sub.3.
[0044] FIG. 35 depicts viscosity of 6-7Psil vinylbenzoate before
(bottom) and after (top) irradiation with 3 wt % Darocur 1173 as
photoinitiator.
[0045] FIG. 36 depicts moduli of 6-7PSil methacrylate before
(bottom curves) and after (top curves) irradiation with 3 wt %
Darocur 1173 as photoinitiator at 1 Hz frequency.
[0046] FIG. 37A depicts the .sup.1H NMR spectrum of hydrolysis
product in CD.sub.3OD.
[0047] FIG. 37B depicts the .sup.1H NMR spectrum of first
extraction product.
[0048] FIG. 37C depicts the .sup.1H NMR spectrum of second
extraction product in CDCl.sub.3.
[0049] FIG. 37D depicts the .sup.1H NMR spectrum of liquid residue
after extraction in D.sub.2O.
[0050] FIG. 37E depicts the .sup.1H NMR spectrum of solid residue
after extraction in CD.sub.3OD of 6-7PSil vinylbenzoate with 3 wt %
Darocur 1173 as photoinitiator after irradiation.
[0051] FIG. 38 depicts DSC diagrams of vinylbenzoic acid (solid)
and polyvinylbenzoic acid (dot for first run and dash for second
run) obtained from solution polymerization.
[0052] FIG. 39 depicts the .sup.1H NMR spectrum of 6-7PSil
methacrylate in CDCl.sub.3.
[0053] FIG. 40A depicts the .sup.1H NMR spectrum of crude
hydrolysis product in D.sub.2O.
[0054] FIG. 40B depicts the .sup.1H NMR spectrum of the first
extraction product in CDCl.sub.3.
[0055] FIG. 40C depicts the .sup.1H NMR spectrum of the second
extraction product in CDCl.sub.3.
[0056] FIG. 41 depicts viscosity of 6-7Psil methacrylate before
(bottom curve) and after (upper curve) irradiation with 3 wt %
Darocur 1173 as photoinitiator.
[0057] FIG. 42 depicts moduli of 6-7PSil methacrylate before
(bottom curve) and after (upper curve) irradiation with 3 wt %
Darocur 1173 as photoinitiator.
[0058] FIG. 43 depicts the viscosity of D.sub.2EDA (bottom curve)
and D.sub.2EDA acrylate before (middle curve) and after (upper
curve) irradiation with 3 wt % Darocur 1173 as photoinitiator.
[0059] FIG. 44 depicts moduli of D.sub.2EDA (bottom curve) and
D.sub.2EDA acrylate (upper curve).
[0060] FIG. 45 depicts moduli D.sub.2EDA acrylate after irradiation
with 3 wt % Darocur 1173 as photoinitiator.
[0061] FIG. 46 depicts vertically offset .sup.1H NMR spectra in
CD.sub.3OD of the hydrolysis product of ammoniumpolysiloxane
vinylbenzoate after irradiation (1), and polyvinylbonzoic acid
obtained from free radical solution polymerization (2).
DETAILED DESCRIPTION
[0062] Aminoalkylfunctional silicones have a broad array of
applications as a result of their chemical reactivity, their
ability to form hydrogen bonds and, particularly in the case of
diamines, their chelating ability. Additional reactivity can be
built into aminoalkyl groups in the form of alkoxy groups.
Aminoalkylsiloxanes are available in the three classes of
structures typical for silicone polymers: terminated, pendant group
and T-structure.
[0063] Aminopropyl terminated polydimethylsiloxanes react to form a
variety of polymers including polyimides, polyureas and
polyurethanes. Block polymers based on these materials are becoming
increasingly important in microelectronic (passivation layer) and
electrical (low-smoke generation insulation) applications. They are
also employed in specialty lubricant and surfactant applications.
They may also be used in antifouling coatings (e.g., as
bactericidal coatings), particularly when the polymer contains
quaternary amines.
[0064] An aspect of the invention is a composition, comprising a
polysiloxane comprising a plurality of pendant amines; and an acid
selected from the group consisting of carboxylic acids, sulfonic
acids, HCl, HBr, HI, HNO.sub.3, H.sub.2SO.sub.4, H.sub.3PO.sub.4,
B(OH).sub.3, HClO.sub.3, and HClO.sub.4.
[0065] In one embodiment, each of the plurality of pendant amines
is attached to the polysiloxane via an alkyl chain optionally
substituted with one or more alkyl, haloalkyl, halide, aryl, or
aralkyl groups.
[0066] In one embodiment, the acid is a carboxylic acid.
[0067] In one embodiment, the acid is a dicarboxylic acid.
[0068] In one embodiment, the acid is a carboxylic acid selected
from the group consisting of acetic acid, ethanoic acid, propionic
acid, pentanoic acid, hexanoic acid, trifluoroacetic acid,
chloroacetic acid, dichloroacetic acid, trichloroacetic acid,
methoxyacetic acid, acrylic acid, methacrylic acid, benzoic acid,
vinylbenzoic acid, oxalic acid, malonic acid, succinic acid,
glutaric acid, adipic acid, azelaic acid, terephthalic acid,
phthalic acid, a perylene dicarboxylic acid, a nitrobenzoic acid,
and a polymer comprising carboxylic acids.
[0069] In one embodiment, the acid is a sulfonic acid.
[0070] In one embodiment, the acid is methanesulfonic acid,
trifluoromethanesulfonic acid, benzenesulfonic acid,
p-toluenesulfonic acid, taurine, and a sulfonic-acid containing
polymer.
[0071] In accordance with any one of the foregoing embodiments, in
one embodiment the pendant amines are primary amines.
[0072] In accordance with any one of the foregoing embodiments, in
one embodiment pendant amines are secondary amines.
[0073] In accordance with any one of the foregoing embodiments, in
one embodiment the pendant amines are tertiary amines.
[0074] In accordance with any one of the foregoing embodiments, in
one embodiment the pendant amines are quaternary amines.
[0075] In accordance with any one of the foregoing embodiments, in
one embodiment the pendant amines are diamines or amidines.
[0076] In accordance with any one of the foregoing embodiments, in
one embodiment the pendant amines are amidines.
[0077] In accordance with any one of the foregoing embodiments, in
one embodiment the pendant amines are substituted with one, two, or
three alkyl, alkenyl, alkynyl, cycloalkyl, aromatic, or alkoxy
groups.
[0078] In accordance with any one of the foregoing embodiments, in
one embodiment the pendant amines are acyclic.
[0079] An aspect of the invention is a composition, comprising a
polysiloxane comprising a plurality of pendant acids selected from
the group consisting of carboxylic acids and sulfonic acids, and an
amine.
[0080] In one embodiment, each of the plurality of pendant acids is
a carboxylic acid.
[0081] In one embodiment, each of the plurality of pendant acids is
a carboxylic acid attached to the polysiloxane via an alkyl chain
optionally substituted with one or more alkyl, haloalkyl, halide,
aryl, or aralkyl groups.
[0082] In one embodiment, each of the plurality of pendant acids is
a sulfonic acid.
[0083] In one embodiment, each of the plurality of pendant acids is
a sulfonic acid attached to the polysiloxane via an alkyl chain
optionally substituted with one or more alkyl, haloalkyl, halide,
aryl, or aralkyl groups.
[0084] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is a primary amine.
[0085] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is a secondary amine.
[0086] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is a tertiary amine.
[0087] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is a quaternary amine.
[0088] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is a diamine or amidine.
[0089] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is an amidine.
[0090] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is substituted with one, two, or three
alkyl, alkenyl, alkynyl, cycloalkyl, aromatic, or alkoxy
groups.
[0091] In accordance with any one of the foregoing embodiments, in
one embodiment the amine is acyclic.
[0092] Preferred embodiments of amino functionality pendant from
the siloxane backbone include:
(aminopropyl)-methylsiloxane-dimethylsiloxane copolymers and
(aminoethylaminopropyl)-methylsiloxane-dimethylsiloxane copolymers.
They are frequently used in modification of polymers such as
epoxies and urethanes, internal mold releases for nylons and as
lubricants, release agents and components in coatings for textiles
and polishes.
[0093] Aminoalkyl T-structure silicones are primarily used as
surface treatments for textiles and finished metal polishes (e.g.,
automotive car polishes). The resistance to wash-off of these
silicones is frequently enhanced by the incorporation of alkoxy
groups which slowly hydrolyze and form crosslink or reactive sites
under the influence of the amine. The same systems can be reacted
with perfluorocarboxylic acids to form low surface energy (<7
dynes/cm) films.
[0094] The amino-functionalized or acid-functionalized polysiloxane
scaffolds may be random or block copolymers. Non-limiting examples
of amino-functionalized polysiloxane scaffolds include the
following:
##STR00001## ##STR00002##
[0095] Replacement of any of the amine groups above with an acidic
moiety such as --COOH, --CH.sub.2COOH, SO.sub.3H, or
CH.sub.2SO.sub.3H, would yield the reversed polymer discussed in
greater detail below.
[0096] The backbone may be modified so that the polymers are based
on alternate polysiloxanes such as diethylsiloxane,
diisopropylsiloxane, diphenylsiloxane, alkoxysiloxanes such as
dimethoxysiloxane or diethoxysiloxane, haloalkylsiloxanes (e.g.,
fluoroalkylsiloxanes), or other polysiloxanes known in the art.
[0097] The mol % of amine functional groups in the polymer may vary
substantially and may be selected to modulate one or more of the
physical properties of the polymer to achieve a desired result. For
example, a more viscous polymer may be obtained by an increase in
the mol % of amine functional groups, leading to more protonation
and thus more ionic interactions per unit of polymer weight. In
certain embodiments, the mol % of the amine functional groups is
about 0.05-0.1%, 0.1-1.0%), or 0.5-1%>. In certain embodiments,
the mol % of the amine functional groups is about 0.05-25%,
0.1-20%, 0.2-15%, 1-12%, 2-10%, 3-8%, 4-7%, 5-6%, 0.05-2%, 0.08-1%,
or 1-2%.
[0098] Selection of a particular average molecular weight of the
polysiloxane polymer will be determined by task at hand. For
example, polymers with higher molecular weights tend to have higher
viscosity, making them more useful in certain applications. In
certain embodiments, the molecular weight is about 700-10,000,
800-9,000, 900-8,000, 1,000-7,000, 2,000-7,000, 3,000-6,000, or
4,000-5,000. Any range of molecular weights may be combined with
any mol % of amine functional group recited above.
[0099] The identity of the amine functionality can greatly impact
the properties of the polysiloxane polymer. Generally speaking, the
amine may be substituted with one to three alkyl, alkenyl, alkynyl,
cycloalkyl, aromatic, or alkoxy groups. The amine itself may be
cyclic or acyclic. The amine may be a primary, secondary, or
tertiary amine. The amine may also be a quaternary amine (e.g., a
trimethylammonium group with a fourth bond to the polysiloxane
chain) and thus bear a permanent positive charge. The amine may
also be converted to an amidine group, which is more basic than a
simple amine.
[0100] The polysiloxane backbone may, in certain embodiments, be
substituted with an acidic moiety instead of an amine. Preferred
acids are carboxylic and sulfonic acids. These acids would
protonate amines or other bases added to the polysiloxane polymer
to form ionic bonds and influence the viscosity and other
properties of the material. Such "reversed" polysiloxane materials
can achieve similar results as those systems in which the amine or
other base is appended to the polysiloxane backbone. Moreover,
monovalent and divalent metal cations may be added to these
systems, providing another basis for influencing the properties of
the compositions.
[0101] Protonation of the amine functional groups of the
polysiloxane by added acid causes the development of a
three-dimensional network mediated by electrostatic interactions.
Such a network is termed an "interpenetrating network" and has
different and advantageous properties compared with intimate
mixtures of polymers. Preferred acids are carboxylic acids or
di-carboxylic acids, for example, formic acid, ethanoic acid,
propionic acid, pentanoic acid, hexanoic acid, trifluoroacetic
acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid,
methoxyacetic acid, acrylic acid, methacrylic acid, benzoic acid,
vinylbenzoic acid, oxalic acid, malonic acid, succinic acid,
glutaric acid, adipic acid, azelaic acid, phthalic acid isomers, a
perylene dicarboxylic acid, a nitrobenzoic acid, and a polymer
containing acidic groups Other preferred acids include sulfonic
acids such as methanesulfonic acid, trifluoromethanesulfonic acid,
benzenesulfonic acid, p-toluenesulfonic acid, taurine, and sulfonic
acid-substituted ion exchange resins (e.g., Naftion). Mineral acids
such as HCl, HBr, HI, HNO.sub.3, H.sub.2SO.sub.4, H.sub.3PO.sub.4,
B(OH).sub.3, HClO.sub.3, and HClO.sub.4 may be used.
[0102] Optically active acids or bases may be added to the basic-
or acidic-functional group-containing polysiloxane. The use of
optically active acids (or bases if the polysiloxane has acidic
groups appended) can create chiral environments so that the
resulting polymers would be useful in enantiomeric sensing and
separations (via chromatography).
[0103] Generally, the acid and base will be in an approximately
stoichiometric (1:1) ratio, whether the amine is pendant on the
polysiloxane polymer or the acid is pendant on the polymer. The
ratio (amine:acid) may also be altered to influence the average
protonation state of the amine functional groups, and may be 1.1:1,
2:1, 3:1, 4:1, or greater than 4:1. In certain embodiments, the
ratio of acid:amine is 1.1:1, 2:1, 3:1, 4:1, or greater than
4:1.
[0104] Poly((amino functional alkoxy)-alkylsiloxane) compounds can
have a variety of uses. For example, such compounds may be useful
as a component of a coating composition. Depending on the
particular application, a poly((aminofunctional
alkoxy)-alkylsiloxane) compound may be used by itself to form a
coating or may be formulated with other components known to those
of skill in the art to form the coating composition. For example, a
poly((aminofunctional alkoxy)-alkylsiloxane) may act as a
crosslinking agent and/or curing accelerator in a coating
composition, e.g., in an epoxy-based coating composition.
[0105] In another embodiment, a poly((aminofunctional
alkoxy)-alkylsiloxane) compound may be used as a "primer" component
in a coating system (e.g., to adhere a topcoat to a substrate). The
primer containing the poly ((aminofunctional alkoxy)-alkylsiloxane)
and a topcoat (e.g., polyurethane may be applied to a substrate
according to the following exemplary method. A substrate (e.g.,
aluminum 2024-T3) may be treated by cleaning its surface with a
solvent (e.g., acetone). The primer may be applied to the substrate
"neat" with an applicator such as a "draw down" bar. The primer may
be dried at ambient temperature for about one day, and cured at
about 45 C for about five hours. The topcoat may be applied to the
primer with an applicator such as a "draw down" bar. The topcoat
may be dried at ambient temperature for about one day, and
subsequently cured at an elevated temperature (e.g., at about
45-50.degree. C. for a period of hours).
[0106] Other uses for the poly((aminofunctional
alkoxy)-alkylsiloxane) compounds include applications in the
production of adhesives, catalyst supports, ionically conductive
materials, liquid crystals, crosslinking agents, conductive and
electroluminescent polymers, electrochemical sensing devices, and
nonlinear optical chromophores.
[0107] It is also contemplated that the materials of the present
invention may be used as controlled-release systems, e.g., as
controlled-release drug delivery) systems. The rate of delivery of
a captured substance, or guest molecule, may be controlled by the
degree of cross-linking present in the polysiloxane.
[0108] Many functionalized polysiloxane materials are commercially
available. They may also be prepared synthetically by methods known
in the art (see, e.g., U.S. Pat. No. 6,482,912, hereby incorporated
by reference).
[0109] The present aminofunctional alkoxy polysiloxane compound can
be a linear and/or cyclic alkoxy polysiloxane. As used herein, the
term "aminofunctional alkoxy polysiloxane compound" refers to an
alkoxy substituted polysiloxane compound which includes one or more
aminofunctional alkoxy groups. For the purposes of this
application, the term aminofunctional alkoxy group refers to groups
which include at least one basic nitrogen atom and encompasses
groups resulting from the removal of a hydroxyl hydrogen atom from
an amino functional alkanol (e.g.,
--O--CH.sub.2CH.sub.2--O--CH.sub.2CH.sub.2NH.sub.2), an amino
functional cycloalkanol, and/or an amino functional
hydroxy-substituted aryl compound (e.g.,
--O--C.sub.6H.sub.4--O--CH.sub.2CH.sub.2NH.sub.2).
[0110] The siloxane subunits may not all contain an aminofunctional
alkoxy group. In certain embodiments, a majority of the siloxane
subunits of the polymer include an aminofunctional alkoxy group.
Polysiloxanes where not all of the siloxane subunits of the polymer
include the same substituents polymer (with the exception of the
terminal subunits) are referred to herein as "polysiloxane
copolymers." As used herein, such "copolymers" can have two or more
different siloxane subunits. Polysiloxane copolymers can be formed
by reacting a mixture of two alcohols, e.g., a mixture of
2-aminoethanol and ethanol, with a polyhydrosiloxane. Generally,
the different siloxane subunits are randomly distributed in a
polysiloxane copolymer (a "random copolymer"). However, by using
appropriate synthetic methods known to those of skill in the art,
polysiloxane copolymers in which the different siloxane subunits
are present in "blocks" of two or more identical adjacent subunits
can also be produced ("block copolymers"). The present polysiloxane
copolymers typically have a ratio of siloxane subunits containing
an aminofunctional alkoxy group to subunits which do not include an
aminofunctional alkoxy group of about 20:1 to 1:20.
[0111] The term "acid" as used herein may include any inorganic or
organic acid.
[0112] The term "base" as used herein may include any inorganic or
organic Bronsted or Lewis base selected from those mentioned above
in addition to non-pharmaceutically acceptable bases that are
efficacious in organic chemistry. Particularly preferred organic
bases are isopropylamine, diethylamine, ethanolamine,
trimethylamine, diisopropylethylamine (DIPEA), dicyclohexylamine,
1,4-diazabicyclo[2.2.2]octane (DABCO),
1,8-Bis(dimethylamino)naphthalene (Proton Sponge), and
1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU).
[0113] The compounds of the invention may contain one or more
asymmetric centers and may thus give rise to enantiomers,
diastereomers, and other stereoisomeric forms that may be defined,
in terms of absolute stereochemistry, as (R)- or (S)- or, as (D)-
or (L)- for amino acids. The present invention is meant to include
all such possible isomers, as well as, their racemic and optically
pure forms. Optically active (+) and (-), (R)- and (S)-, or (D)-
and (L)-isomers may be prepared using chiral synthons or chiral
reagents, or resolved using conventional techniques, such as
reverse phase HPLC. When the compounds described herein contain
olefinic double bonds or other centers of geometric asymmetry, and
unless specified otherwise, it is intended that the compounds
include both E and Z geometric isomers. Likewise, all tautomeric
forms are also intended to be included.
[0114] The term "alkyl" as used herein is intended to include
linear, branched, or cyclic hydrocarbon structures and combinations
thereof. Lower alkyl (or haloalkyl) refers to alkyl (haloalkyl)
groups of from 1 to 6 carbon atoms. Examples of lower alkyl groups
include methyl, ethyl, propyl, isopropyl, butyl, s- and t-butyl and
the like. Preferred alkyl groups are those of C.sub.20 or below.
More preferred alkyl groups are those of C.sub.12 or below.
Cycloalkyl is a subset of alkyl and includes cyclic hydrocarbon
groups of from 3 to 12 carbon atoms. Examples of cycloalkyl groups
include c-propyl, c-butyl, c-pentyl, norbornyl, adamantyl and the
like. The terms "alkenyl" and "alkynyl" have identical chain
lengths as mentioned above for "alkyl", but have one or more double
or triple bonds in the carbon chain or at the two terminal
positions of the carbon chain, respectively. "Alkylene" refers to
the same residues as alkyl, but having two points of attachment.
Examples of alkylene include ethylene (--CH.sub.2CH.sub.2--),
propylene (--CH.sub.2CH.sub.2CH.sub.2--), dimethylpropylene
(--CH.sub.2C(CH.sub.3).sub.2CH.sub.2--) and cyclohexylpropylene
(--CH.sub.2CH.sub.2CH(C.sub.6H.sub.13)--). When an alkyl residue
having a specific number of carbons is named, all geometric isomers
having that number of carbons are intended to be encompassed; thus,
for example, "butyl" is meant to include cyclobutyl, in-butyl,
sec-butyl, isobutyl and i-butyl; "propyl" includes cyclopropyl,
n-propyl and isopropyl.
[0115] "Alkoxy" or "alkoxyl" refers to groups of from 1 to 8 carbon
atoms of a straight, branched, cyclic configuration and
combinations thereof attached to the parent structure through an
oxygen. Examples include methoxy, ethoxy, propoxy, isopropoxy,
cyclopropyloxy, cyclohexyloxy and the like. Lower alkoxy refers to
groups containing one to four carbons.
[0116] "Acyl" refers to groups of from 1 to 8 carbon atoms of a
straight, branched or cyclic configuration, or a combination of any
such configurations, attached to the parent structure through a
carbonyl functionality. Such acyl groups can be saturated or
unsaturated, and aromatic or non-aromatic. One or more carbons in
the acyl residue can be replaced by nitrogen, oxygen or sulfur as
long as the point of attachment to the parent remains at the
carbonyl. Examples include acetyl, benzoyl, propionyl, isobutyryl,
t-butoxycarbonyl, benzyloxycarbonyl and the like. Lower acyl refers
to groups containing one to four carbons.
[0117] "Aryl" means a 5- or 6-membered aromatic or heteroaromatic
ring containing 0-3 heteroatoms selected from O, N, or S; a
bicyclic 9- or 10-membered aromatic or heteroaromatic ring system
containing 0-3 heteroatoms selected from O, N, or S; or a tricyclic
13- or 14-membered aromatic or heteroaromatic ring system
containing 0-3 heteroatoms selected from O, N, or S. The aromatic
6- to 14-membered carbocyclic rings include, e.g., benzene,
naphthalene, indane, tetralin, and fluorene, and the 5- to
10-membered aromatic heterocyclic rings include, e.g., imidazole,
pyridine, indole, thiophene, benzopyranone, thiazole, furan,
benzimidazole, quinoline, isoquinoline, quinoxaline, pyrimidine,
pyrazine, tetrazole and pyrazole.
[0118] "Aralkyl" refers to a residue in which an aryl moiety is
attached to an alkyl residue. Examples are benzyl, phenethyl,
phenylvinyl, phenylallyl and the like.
[0119] "Oxaalkyl" and "oxaaralkyl" refer to alkyl and aralkyl
residues in which one or more methylenes have been replaced by
oxygen. Examples of oxaalkyl and oxaalkylaryl residues are
ethoxyethoxyethyl (3,6-dioxaoctyl), benzyloxymethyl and
phenoxymethyl; in general, glycol ethers, such as poly
ethyleneglycol, are intended to be encompassed by this group.
[0120] "Heteroaralkyl" refers to a residue in which a heteroaryl
moiety is attached to the parent structure via an alkyl residue.
Examples include furanylmethyl, pyridinylmethyl, pyrimidinylethyl
and the like.
[0121] "Heterocyclyl" means a cycloalkyl or aryl residue in which
one to four of the carbons is replaced by a heteroatom, such as
oxygen, nitrogen or sulfur. Examples of heterocycles that fall
within the scope of the invention include imidazoline, pyrrolidine,
pyrazole, pyrrole, indole, quinoline, isoquinoline,
tetrahydroisoquinoline, benzofuran, benzodioxan, benzodioxole
(commonly referred to as methylenedioxyphenyl, when occurring as a
substituent), tetrazole, morpholine, thiazole, pyridine,
pyridazine, pyrimidine, thiophene, furan, oxazole, oxazoline,
isoxazole, dioxane, tetrahydrofuran and the like. "N-heterocyclyl"
refers to a nitrogen-containing heterocycle as a substituent
residue. The term heterocyclyl encompasses heteroaryl, which is a
subset of heterocyclyl. Examples of N-heterocyclyl residues include
4-morpholinyl, 4-thiomorpholinyl, 1-piperidinyl, 1-pyrrolidinyl,
3-thiazolidinyl, piperazinyl and 4-(3,4-dihydrobenzoxazinyl).
Examples of substituted heterocyclyl include 4-methyl-1-piperazinyl
and 4-benzyl-1-piperidinyl.
[0122] Substituted alkyl, aryl and heteroaryl refer to alkyl, aryl
or heteroaryl wherein one or more hydrogen atom(s) is replaced with
alkyl, halogen, hydroxy, alkoxy, alkylenedioxy (e.g.,
methylenedioxy) fluoroalkyl, carboxy (--COOH), carboalkoxy (i.e.,
acyloxy RCOO--), carboxyalkyl (--COOR), carboxamido,
sulfonamidoalkyl, sulfonamidoaryl, aminocarbonyl,
benzyloxycarbonylamino (CBZ-amino), cyano, carbonyl, nitro,
dialkylamino, alkylamino, amino, alkylthio, alkylsulfinyl,
alkylsulfonyl, alkylsulfonamido, arylthio, arylsulfinyl,
arylsulfonyl, amidino, phenyl, benzyl, heteroaryl, heterocyclyl,
substituted heterocyclyl, phenoxy, benzyloxy, or heteroaryloxy. For
the purposes of the present invention, substituted alkyl also
includes oxaalkyl residues, i.e., alkyl residues in which one or
more carbons has been replaced by oxygen. Preferred substitutions
include alkyl, alkenyl, alkynyl, halogen, hydroxy, alkoxy,
fluoroalkyl, cyano, carbonyl, nitro, dialkylamino, alkylamino,
amino, alkylthio, aralkyl, heteroaryl, and heterocyclyl.
[0123] "Halogen" refers to fluorine, chlorine, bromine or iodine.
Fluorine, chlorine and bromine are preferred. Dihaloaryl,
dihaloalkyl, trihaloaryl, etc., refer to aryl and alkyl substituted
with a plurality of halogens, but not necessarily a plurality of
the same halogen; thus 4-chloro-3-fluorophenyl is within the scope
of dihaloaryl.
[0124] The terms "solvent", "inert organic solvent" or "inert
solvent" mean a solvent inert under the conditions of the reaction
being described in conjunction therewith. Solvents employed in
synthesis of the compounds of the invention include, for example,
methanol, acetone, water, acetonitrile, 1,4-dioxane,
dimethylformamide, benzene, toluene, tetrahydrofuran, chloroform,
methylene chloride (or dichloromethane), diethyl ether, tert-butyl
methyl ether (TBME), pyridine and the like, as well as mixtures
thereof. Unless specified to the contrary, the solvents used in the
reactions of the present invention are inert organic solvents.
[0125] As used herein, the term "hydroxyl" means --OH.
[0126] As used herein, the term "nitro" means --N0.sub.2.
[0127] As used herein, the term "thiol" means --SH.
[0128] As used herein, the term "sulfonyl" means --SO.sub.2--.
[0129] As used herein, the term "disulfide" refers to any chemical
compound that comprises a covalently linked pair of sulfur atoms
(disulfide bond), e.g., diphenyl disulfide
(C.sub.6H.sub.5--S--S--C.sub.6H.sub.5).
[0130] The terms "amine" and "amino" are art-recognized and refer
to both unsubstituted and substituted amines, e.g., a moiety that
can be represented by the general formula:
##STR00003##
wherein R.sup.101, R.sup.102 and R.sup.103 each independently
represent hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl,
--(CH.sub.2).sub.mR.sup.200, wherein m is an integer 1-10 and
R.sup.200represents a group permitted by the rules of valence, such
as hydrogen, alkyl, alkenyl, alkynyl, aryl, and heteroaryl. An
"amine" or "amino" moiety may be a cyclic amine (e.g., piperidine
or quinine).
[0131] The term "amino" also includes "acylamino," which is
art-recognized and refers to a moiety that can be represented by
the general formula:
##STR00004##
wherein R.sup.101 is as defined above, and R.sup.104 represents
hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl or
--(CH.sub.2).sub.nR.sup.200, wherein m and R.sup.200 are defined
above.
[0132] The term "amido" is art-recognized as an amino-substituted
carbonyl and includes a moiety that can be represented by the
general formula:
##STR00005##
wherein R.sup.101 and R.sup.102 are as defined above. Preferred
embodiments of the amide will not include those which are
unstable.
[0133] The term "alkylthio" refers to an alkyl group, as defined
above, having a sulfur radical attached thereto. In preferred
embodiments, the "alkylthio" moiety is represented by one of
--S-alkyl, --S-alkenyl, --S-alkynyl, and
--S--(CH.sub.2).sub.m--R.sup.200, wherein m and R.sup.200 are
defined above.
[0134] Representative alkylthio groups include methylthio and
ethylthio.
[0135] The term "carbonyl" is art-recognized and includes such
moieties as can be represented by the general formula:
##STR00006##
wherein X is a bond or represents an oxygen or a sulfur, and
R.sup.105 represents a hydrogen, alkyl, alkenyl, alkynyl, aryl,
heteroaryl or --(CH.sub.2).sub.mR.sup.200, wherein m and R.sup.200
are defined above, or a pharmaceutically acceptable salt, and
R.sup.106 represents hydrogen, alkyl, alkenyl, alkynyl, aryl,
heteroaryl or --(CH.sub.2).sub.mR.sup.200, wherein m and R.sup.200
are defined above. Where X oxygen and R.sup.105 or R.sup.106 is not
hydrogen, the formula represents an "ester". Where X is oxygen and
R is as defined above, the moiety is referred to herein as a
carboxyl group, and particularly when R.sup.105 is hydrogen, the
formula represents a "carboxylic acid". Where X is oxygen and
R.sup.106 is hydrogen, the formula represents a "formate". In
general, where the oxygen atom of the above formula is replaced by
sulfur, the formula represents a "thiocarbonyl" group. Where X is a
sulfur and R.sup.105 or R.sup.106 is not hydrogen, the formula
represents a "thioester." Where X is sulfur and R.sup.105 is
hydrogen, the formula represents a "thiolcarboxylic acid." Where X
is a sulfur and R.sup.106 is hydrogen, the formula represents a
"thiolformate." On the other hand, where X is a bond and R.sup.105
is not hydrogen, the above formula represents a "ketone" group.
Where X is a bond, and R.sup.106 is hydrogen, the above formula
represents an "aldehyde" group.
[0136] The terms "alkoxyl" or "alkoxy" as used herein refer to an
alkyl group, as defined above, having an oxygen radical attached
thereto. Representative alkoxyl groups include methoxy, ethoxy,
propyloxy, t-butoxy and the like.
[0137] An "ether" is two hydrocarbons covalently linked by an
oxygen. Accordingly, the substituent of an alkyl that renders that
alkyl an ether is or resembles an alkoxyl, such as can be
represented by one of --O-alkyl, --O-alkenyl, --O-alkynyl, and
--(CH.sub.2).sub.m--R.sup.200, where m and R.sup.200 are as defined
above.
[0138] The term "heteroatom" as used herein means an atom of any
element other than carbon or hydrogen. Preferred heteroatoms are
nitrogen, oxygen, sulfur, phosphorus and selenium. In one
embodiment, a heteroatom is selected from nitrogen, oxygen, and
sulfur. In one embodiment, a heteroatom is selected from nitrogen
and oxygen. In one embodiment, a heteroatom is nitrogen. In one
embodiment, a heteroatom is oxygen.
[0139] An aspect of the invention is a method of preparing a
composition of the invention, comprising the step of combining a
polysiloxane comprising a plurality of pendant amines; and an acid
selected from the group consisting of carboxylic acids, sulfonic
acids, HCl, HBr, HI, HNO.sub.3, H.sub.2SO.sub.4, H.sub.3PO.sub.4,
B(OH).sub.3, HClO.sub.3, and HClO.sub.4.
[0140] In one embodiment, the method further comprises the step of
irradiating the composition.
[0141] An aspect of the invention is a method of preparing a
composition of the invention, comprising the step of combining a
polysiloxane comprising a plurality of pendant acids selected from
the group consisting of carboxylic acids and sulfonic acids; and an
amine.
[0142] In one embodiment, the method further comprises the step of
irradiating the composition.
[0143] An aspect of the invention is a battery, comprising a
composition of the invention.
[0144] In one embodiment, the battery further comprises a plurality
of lithium ions.
[0145] An aspect of the invention is a composition for controlled
release of a compound, comprising a composition of the invention;
and the compound.
[0146] In one embodiment, the compound is an active pharmaceutical
ingredient.
EXEMPLIFICATION
[0147] As will be apparent to those of skill in the art upon
reading this disclosure, each of the individual embodiments
described and illustrated herein has discrete components and
features which may be readily separated from or combined with the
features of any of the other several embodiments without departing
from the scope or spirit of the present invention. Any recited
method can be carried out in the order of events recited or in any
other order which is logically possible. The invention now being
generally described, it will be more readily understood by
reference to the following, which is included merely for purposes
of illustration of certain aspects and embodiments of the present
invention, and is not intended to limit the invention.
Example 1
General Procedures; 6-7PSil Carboxylates
[0148] Materials.
[0149] (3-Aminopropyl)methylsiloxane-co-dimethylsiloxane copolymer
with 6-7% monomer units with amino groups (6-7PSil; Gelest, Inc.;
characterization data from supplier: bp>205.degree. C.,
mp<-60.degree. C., molecular weight: 3000-6000, viscosity:
0.08-0.12 Pas) and N-(2-aminoethyl)-3-aminopropylmethylpolysiloxane
(D.sub.2EDA; Siltech, Inc.; characterization data from supplier:
molecular weight: 1700 and one primary amino and one secondary
amino group in 23% of the monomer units) were used as received.
Acetic acid (EM Science, 99.7%), propionic acid (Mallinckrodt, AR,
99.95%), trifluoroacetic acid (Acros, 99%), benzoic acid
(Sigma-Aldrich, 99%), acrylic acid (Aldrich, 99%), oxalic acid
(Acros, 98%), malonic acid (Sigma-Aldrich, 99%), succinic acid
(Aldrich, 99+%), glutaric acid (Aldrich, 99%), azelaic acid
(Aldrich, 98%), succinic acid (Aldrich, 99+%), glutaric acid
(Aldrich, 99%), azelaic acid (Aldrich, 98%), vinylbenzoic acid
(Fisher, 97%), azobisisobutyronitrile (AIBN, Aldrich, 98%),
tert-butylamine (Aldrich, 98%), tributylamine (Aldrich, 98%)
1,4-dioxane (Sigma-Aldrich, anhydrous, 99.8%), diethyl ether (EMD,
>980%), ethyl acetate (Sigma-Aldrich, ACS reagent, >99.5%),
chloroform (Sigma-Aldrich, ACS reagent, >99.8%),
2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocur 1173, Ciba), and
methylene chloride (Fisher Scientific, HPLC Grade) were used as
received.
[0150] Instrumentation.
[0151] Thermogravimetric analysis (TGA) measurements were performed
on a TGA Q50 thermogravimetric analyzer (TA Instruments, New
Castle, Del.) interfaced to a computer. Samples of 2-10 mg were
heated at 10.degree. C./min under a slow stream of nitrogen.
Differential scanning calorimetry (DSC) measurements were performed
on a Q200 calorimeter (TA Instruments, New Castle, Del.) interfaced
to a TA Thermal Analyst 3100 controller that was connected to an
RCS90 cooling system. Samples were placed in open Tzero pans. Both
the heating and cooling rates were 10.degree. C./min and
measurements were made under a slow stream of nitrogen. Rheological
measurements were performed with an Anton Paar Physica MCR 301
strain-controlled rheometer (Anton Paar GmbH, Graz, Austria),
equipped with a Peltier temperature controller and parallel plates
(25 mm diameter) at 25.degree. C. The data were collected using
Rheoplus/32 Service V3.10 software. Before data were recorded, each
sample was placed directly onto the steel base plate, and the upper
parallel steel plate was moved into the 0.5 mm initial gap and
contact with the upper sample surface, after which any excess
substrate sample was removed. Then, the samples were kept
undisturbed at 25.degree. C. for 5 min to ensure thermal
equilibration. For viscosity and moduli measurement, 25 data points
were recorded. Duplicate measurements were performed with new
samples. .sup.1H NMR spectra were recorded on a Varian 400 MHz
spectrometer (Varian Inc. CA, USA) with VnmrJ software using
tetramethylsilane as the internal standard. Each spectrum was based
upon 64 FIDs. IR spectra were recorded on a Nicolet 380 FT-IR
spectrometer (Thermo Electron, MA, USA) with Omnic software
(average of 32 spectra with 4 cm.sup.-1 resolution). Liquid samples
were placed as films between NaCl windows. All experiments were
conducted at room temperature unless indicated otherwise.
[0152] Adhesion Test.
[0153] Room temperature adhesion of synthesized polymers to
surfaces was measured by two different methods. In method 1, based
on extensional rheology, data were collected on the rheometer and
analyzed with Rheoplus/32 Service V3.10 software. Samples were
placed directly onto the steel base plate, and the upper parallel
steel plate was moved to an initial 0.5 mm gap so that the sample
was in complete contact with the upper plate. After excess sample
was removed, the samples were equilibrated at 25.degree. C. for 5
min. Then, the top plate was lifted vertically at 1 .mu.m/s until
the normal force did not change (i.e., the film was broken
completely). The normal force response in this process was recorded
by the rheometer, and the maximum force is reported. Additional
measurements were performed with new aliquots of the same
samples.
[0154] Method 2 employed an Instron 3345 (Instron Co. MA, USA)
universal testing machine, with a 5 kN load, controlled by Bluehill
software in the extension mode according to the ISO 4587:2003
protocol. The sample holder was composed of three glass slides
(10.0 cm.times.2.50 cm.times.2.38 mm). One end of two of the plates
was attached vertically to the upper and lower fixtures of the
machine. The third slide was placed parallel to and overlapping the
other two. One-half of the third plate was bonded by epoxy adhesive
(ATACS, 5104/4103) to one of the other plates and a film of 1.25
cm.times.2.50 cm cross-sectional area and ca. 100 .mu.m thickness
was placed in contact with the other half and one-half of the third
plate. The film thickness was controlled by placing a polyethylene
film spacer (DuPont Sclairfilm LLDPE Film, 4 mils) between the two
plates. Thereafter, the upper grip was pulled vertically at 20
mm/min until the polymer layer was broken totally. The force during
the vertical motion was recorded as a function of extension
distance and time, and the maximum force is reported.
[0155] The data shown in the Figures are averages of three trials,
and the error bars represent one standard deviation.
[0156] Syntheses of Ammoniumpolysiloxane Carboxylates.
[0157] The amine contents were calculated to be
8.50.times.10.sup.-4; mol/g (6.5% amine content) for 6-7PSil by
potentiometric titrations with trifluoroacetic acid in ethanol and
4.46.times.10.sup.-3 mol/g (one primary amino and one secondary
amino group in 23% of the monomer units) for D.sub.2EDA as
calculated from the amine value supplied by the manufacturer.
[0158] Ammoniumpolysiloxane carboxylates with a solid acid (benzoic
acid, oxalic acid, malonic acid, succinic acid, glutaric acid, or
azelaic acid) were synthesized by refluxing and stirring known
weights of aminopolysiloxane and a carboxylic acid and methylene
chloride (2-3 times the mass of polysiloxane) for 3 h. The solvent
was removed by placing the sample sequentially on a rotary
evaporator, under dynamic reduced pressure at 150 mm Hg for >24
h at room temperature, and under dynamic reduced pressure of 0.5 mm
Hg for 3 h at 40-50.degree. C. Ammoniumpolysiloxane carboxylates
with a liquid acid (acetic acid, propionic acid, trifluoroacetic
acid, acrylic acid, or methacrylic acid) were synthesized by
stirring known weights of aminopolysiloxane, and a carboxylic acid
at room temperature for 1 h, followed by refluxing and stirring for
3 h after adding methylene chloride (2-3 times mass of
polysiloxane). The solvent from the reaction mixtures was removed
sequentially on a rotary evaporator under dynamic reduced pressure
of 150 mm Hg for >24 h at room temperature, and under dynamic
reduced pressure of 0.5 mm Hg for 3 h at 40-50.degree. C.
[0159] Synthesis of Poly(Acrylic Acid).
[0160] Acrylic acid (613 mg) and 300 mg Darocur 1173 (as
photoinitiator) in 10 g 1,4-dioxane was sealed in a Pyrex vial and
irradiated for 1 h. The radiation led to some warming of the
sample. It was cooled to room temperature and poured slowly into
200 mL of stirred acetone. The light yellow solid that precipitated
was washed with three 30 mL aliquots of acetone and dried at
50.degree. C. under dynamic reduced pressure of 150 mm Hg for
>24 h to yield 78% of polymer.
[0161] Synthesis of Poly(Vinylbenzoic Acid).
[0162] Nitrogen gas was bubbled through a solution of 1.0 g
vinylbenzoic acid and 20 mg AIBN (azobisbutyronitrile) in 10 g
1,4-dioxane for 30 min. The solution was stirred and heated at
85-90.degree. C. for 3 h under a nitrogen atmosphere. The solution
was cooled to room temperature and poured slowly into 200 mL of
stirred ether. The yellow solid that precipitated was washed with
three 30 mL aliquots of chloroform and dried at 50.degree. C. under
dynamic reduced pressure of 150 mm Hg for >24 h to yield 67%>
of polymer.
[0163] Irradiations.
[0164] Samples for irradiation were prepared by placing an
ammoniumpolysiloxane acrylate and 3 wt % Darocur 1173 (as
photoinitiator) into sealed, transparent Pyrex vials under air and
stirring for 10 min in the dark. The vials were irradiated with a
450 W medium pressure mercury lamp (Hanovia, PC451050) for 1 h at 8
cm distance.
[0165] Tributylamine or tert-butylamine and one molar equivalent
acrylic acid at 8.50.times.10.sup.4 mol/g concentrations in
methanol were placed in sealed Pyrex vials under air and irradiated
with stirring at room temperature 1 h. White solids were obtained
after removing the solvent under dynamic reduced pressure at 150 mm
Hg for >24 h at 50.degree. C.
[0166] Post-Irradiation Treatment Protocols.
[0167] In one experiment, 178 mg of an irradiated sample of 6-7PSil
and acrylic acid and 15.8 g of 20 wt % trifluoroacetic acid were
stirred for 3 h at 65.degree. C. followed by filtration and removal
of the liquid on a rotary evaporator. In another experiment, 270 mg
of irradiated 6-7PSil and acrylic acid and 50 mL of 1 M
hydrochloric acid were stirred for 3 h at 65.degree. C. and then
treated as before. Also, 100 mg of an irradiated acrylate sample
and 50 mL of 0.25 M NaOH aqueous solution were stirred at room
temperature for 3 h. No signals expected of a poly(acrylic acid)
product or acrylic acid were discernible in the resulting .sup.1H
NMR spectra from these experiments.
[0168] Also, 100 mg of an irradiated 6-7PSil-acrylate sample was
stirred in 50 mL of 0.25 M NaOH aqueous solution at 65.degree. C.
for 3 h, filtered, and part of the liquid was dried. The remainder
of the liquid was extracted with 3.times.30 mL aliquots of ether,
ethyl acetate, and methylene chloride sequentially. Removal of the
combined organic liquids led to no discernible residue. The aqueous
liquid was treated with 1 M HCl to pH=2-3 followed by extraction
with the same solvents as indicated above. The organic and aqueous
liquids were evaporated to residue separately, neither showed peaks
indicative of an acrylate-derived material.
[0169] 100 mg of an irradiated 6-7PSil-vinylbenzoate (or
6-7PSil-methacrylate) sample was stirred in 50 mL of 0.25 M NaOH
aqueous solution at 65.degree. C. for 3 h, filtered, and part of
the liquid was dried. The remainder of the liquid was extracted
with 3.times.30 mL aliquots of ether, ethyl acetate, and methylene
chloride sequentially. Removal of the combined organic liquids led
to no discernible residue. The aqueous liquid was treated with 1 M
HCl to pH=1-2 followed by extraction with the same solvents as
indicated above.
[0170] Swelling Experiments.
[0171] A weighed aliquot (ca. 50 mg) of polymer sample and 3 mL of
a liquid were placed in a closed screw cap glass vial for 24 h. The
polymer was removed, its surface was dried quickly on a piece of
filter paper, and it was reweighed. The swelling ratio (S %) was
calculated by following equation, where Wg and Wp are the weights
of swelled and dry polymer, respectively.
S%(w/w)=[(Wg-Wp)/Wp]100%
[0172] Results and Discussion.
[0173] 6-7PSil was used in all experiments except for FTIR
measurements. Due to its higher amino content (and stronger peak
absorbances in the regions of interest in the IR region),
D.sub.2EDA was used to synthesize and analyze an ammonium acetate
(vide infra). The ammoniumpolysiloxane carboxylates from 6-7PSil
and mono- and di-carboxylic acids (Scheme 1) are listed in Table
1.
##STR00007##
[0174] Spectroscopic evidence for the formation of the
ammoniumpolysiloxane carboxylates was obtained by IR spectroscopy.
Absorption peaks for the amine functional groups of 6-7PSil were
too weak to be detected. Although the relevant IR peaks of
D.sub.2EDA, which contains ca. 23% of the monomer units with one
primary and one secondary amino group, could be detected easily
(FIG. 1), electrostatic repulsion between vicinal ammonium groups
probably limits the fraction of them that are formed when even more
than one equivalent of acetic acid was added. However, no C.dbd.O
peak indicative of free acetic acid (.about.1706 cm.sup.-1) and no
--NH.sub.2 peak (.about.1578 cm.sup.-1) can be detected in the
spectrum of the product from reaction between D.sub.2EDA and one
equivalent of acetic acid, a peak attributed to --NH.sub.3 (1565
cm.sup.-1) is apparent, however.
TABLE-US-00001 TABLE 1 Carboxylic acids and ammoniumpolysiloxane
carboxylates examined. Salt Acid R R' pKa(s).sup.1 acronym Acetic
CH.sub.3-- 4.74 PM1 Propionic CH.sub.3CH.sub.2-- 4.87 PM2
Trifluoroacetic CF.sub.3-- 0.23 PMCF3 Acrylic H.sub.2C.dbd.CH--
4.35 PMAA Methacrylic CH.sub.2.dbd.C(CH.sub.3)-- 4.65 PMMA Benzoic
C.sub.6H.sub.5-- 4.19 PMPh Vinyl benzoic
H.sub.2C.dbd.CHC.sub.6H.sub.5-- 4.29 PMVPh Oxalic N/A 1.27, 4.28
PD0 Malonic --(CH2)-- 2.83, 5.70 PD1 Succinic --(CH2).sub.2-- 4.19,
5.64 PD2 Glutaric --(CH2).sub.3-- 4.35, 5.42 PD3 Adipic
--(CH2).sub.4-- 4.43, 5.41 PD4 Azelaic --(CH.sub.2).sub.7-- 4.55,
5.50 PD7 Carboxylates derived from vinylbenzoic and methacrylic
acids were also prepared, as detailed elsewhere. .sup.1H NMR
spectra of 6-7PSil and one equivalent of trifluoroacetic acid at
different times after mixing are shown in FIG. 2. At 0.5 h, the
amine peak (at 1.2 ppm) was reduced significantly and two new peaks
appeared at 2.0 and 7.5 ppm. At longer times, the peak at 2.0 ppm
gradually decreased, but the peak at 7.5 ppm, assigned to the
ammonium protons, increased and broadened. .sup.1H NMR spectra of
6-7PSil with different molar equivalents of benzoic acid, a weaker
acid (FIG. 11), produced analogous ammonium peaks. As the molar
ratio of acid was increased, the amine peak at 1.2 ppm gradually
decreased, and a new peak, which moved progressively to lower
fields and broadened as the acid concentration increased,
appeared.
[0175] Studies in very polar, uncharged media (such as DMSO)
indicate that the strengths of acids are not as sensitive to
substituent effects as they are in water (see Jaworski, J. S. J.
Chem. Soc, Perkin Trans. 2 2000, 5, 1029-1031 and Taft, R. W. et
al. Accts. Chem. Res. 1988, 21, 463-469). In ionic liquids
(solvents that approximate the local environments experienced by
carboxylic acids in 6-7PSil after conversion of the amino groups to
ammonium cations), fewer data are available, and the acidity values
of solutes depend upon the structure of the cationic and anionic
portions of the media (see, e.g., Varinia S. et al. J. Phys. Chem.
B, 2012, 116, 9122-9129 and Deng, H. et al. J. Org. Chem. 2012, 77,
7291-7298). However, it is clear that, again, the influence of
substituents of a carboxylic acid on its pKa value should be
attenuated with respect to values found in water. Thus, we expect
that the interactions of the set of mono-acids in Table 1 with
6-7PSil will depend more on their shapes than on their pKa values
in water. The dependence of the set of di-acids is more difficult
to predict because electrostatic factors will vary with the
distance between the carboxylic acid/carboxylate groups.
[0176] Electrostatic interactions, ionic crosslinks, and chain
entanglements are known to alter the rheological properties of
polymers. Both static and dynamic rheological investigations were
performed on 6-7PSil with and without the presence of a carboxylic
acid. The steady-shear viscosities of 6-7PSil and its carboxylates
were independent of shear rate (FIG. 12). Their average values for
the whole of the regions measured are listed in FIG. 3. The
viscosity of 6-7PSil is very low, 0.2 Pas; much larger values were
found for that of the ammonium carboxylate salts. Even the 6-7PSil
salt with the structurally simplest and smallest mono-acid, acetic
acid, exhibited a viscosity that is about 27 times larger than that
of 6-7PSil. The viscosities of the salts increased in the order of
trifluoroacetate>benzoate>propionate>acetate. We
hypothesize that the larger size of the propionate and benzoate and
the stronger acidity of trifluoroacetic acid increase electrostatic
interactions by increasing inter-chain ionic interactions.
[0177] Viscosities of the di-acid ammonium salts were much larger
than those of the mono-acid ammonium salts. However, offering a
rationalization for the chain length dependence of the viscosities
within the diacid-based salts is much more difficult: the viscosity
of the oxalate salt (R'=no atom in Table 1) was lower than that of
the succinate (R'.dbd.(CH.sub.2).sub.2), but the viscosities of
both the malonate (R'.dbd.CH.sub.2) and glutarate salts
(R'.dbd.(CH.sub.2).sub.3) were lower than that of the oxalate. We
conjecture that the conformation of the linking ethylene chain
between the carboxylate groups in the succinate (or factors related
to and convoluted with it) are responsible for its extraordinarily
large viscosity. Additional experiments need to be conducted in
order to discern the actual causes of the observed dependence of
viscosity on chain length of the diacids.
[0178] The storage modulus (G') and loss modulus (G'') of 6-7PSil
and its ammonium salts were also measured in strain sweeps (FIG. 5C
and FIG. 13-21), and the moduli reported in FIG. 4 are at 1.2%
strain (i.e., in the linear viscoelastic regimes). The trend in
these moduli follows that of the viscosities: G' and G'' of the
mono-acid ammoniumpolysiloxane carboxylates are higher than that of
6-7PSil and decrease in same order as the viscosities. Both G' and
G'' of the di-acid ammoniumpolysiloxane carboxylates are much
larger than those of the mono-acid systems, and, generally, they
increase as the spacer between the carboxylate groups becomes
shorter (FIG. 5A). Again, succinic acid is an exception, although
its moduli were not as large as those of the oxalate salt.
Furthermore, none of the salts, except the succinate, behaves
rheologically like a gel: G' is smaller than G'' throughout the
frequency range investigated (FIG. 22-28). A frequency sweep in the
linear viscoelastic region of the succinate salt showed that G'
remains larger than G'' at angular frequencies <31 rad/s (FIG.
5B); the ammoniumpolysiloxane succinate salt is a gel-like material
at low frequencies, albeit a weak one.
[0179] The viscosities and G'' values of ammonium carboxylates with
different mole ratios of benzoic acid and acetic acid to amino
groups in 6-7PSil were also investigated (FIGS. 29 and 30). The
magnitudes of both properties increased with increasing acid
concentrations and reached maxima at ca. 110% molar ratios. The
reason for the initial increases can be attributed to the creation
of more electrostatic crosslinks (i.e., pairs of cations and anions
on different chains becoming associated). The reason for the
maximum occurring at greater than 1:1 molar ratios of acid to
6-7PSil is probably a consequence of both entropic and to
electrostatic factors: as the fraction of amino groups of the
6-7PSil that are protonated is increased, the ability of the
remaining amino groups to add a proton decreases due to
electrostatic repulsion. Even at a slight excess of acid, where the
maxima in viscosity and G'' are observed, it is highly probable
that some of the amino groups remain unprotonated; our analytical
methods are not capable of detecting very small amounts of
unprotonated amino groups. Addition of even more acid may disturb
the ordering of inter-chain electrostatic interactions between
protonated amino groups, leading to more fluid materials.
[0180] The relative strengths of adhesion of films of some of the
salts have been determined qualitatively by extensional rheology.
The maximum force necessary to break the films was measured while
increasing the gap between the steel plates of our rheometer. This
force is a relative value, because it depends strongly on the rate
of plate separation, the initial gap (i.e., film thickness), and
plate area. In the experiments described, these factors have been
maintained constant. The maximum normal forces of the ammonium
carboxylates are much larger than that of 6-7PSil (.about.0.01 N)
from which they were derived, and they correlate with the
(absolute) values of the viscosities and moduli (FIG. 6). In
addition, the relative shear force required to break films adhering
to glass of some of the salts were measured using a universal
testing machine (FIG. 7). The trend is similar to that found using
extensional rheology.
[0181] Materials Obtained from Free Radical-Initiated
Polymerization of Olefin-Containing Carboxylic Acid Monomers.
[0182] Photo-initiated (by irradiation in the presence of added
radical initiator such as Darocur 1173, which is
2-hydroxy-2-methyl-1-phenyl-propan-1-one), free-radical reaction of
the 6-7PSil ammonium acrylate led to large increases in the
viscosities (FIG. 8) and G' and G'' values (FIG. 9), suggesting
that the expected polyacrylate had been formed. In addition, the
adhesion of the polymerized material increased significantly (FIG.
10): the normal force increased from 0.13 N before irradiation to
5.40 N after it. By comparison (and again, as expected), no
increase in adhesion was found when a sample of 6-7PSil ammonium
propionate was irradiated in the presence of the same concentration
of 2-hydroxy-2-methyl-1-phenyl-propan-1-one (FIG. 31-33).
[0183] By contrast, vinylbenzoic acid was polymerized when it was
irradiated in 6-7PSil in the presence of the free-radical
initiator. From FIG. 9, it can be seen that the viscosity, moduli
and normal force of the ammoniumpolysiloxane vinylbenzoate
increased markedly after irradiation. Although these changes were
observed qualitatively as well when the ammoniumpolysiloxane
acrylate was irradiated, a white solid, identified as
poly(vinylbenzoic acid) (FIG. 10) was isolated when the irradiated
sample was extracted as described in the Experimental Part. The
material prepared by irradiation of ammoniumpolysiloxane
vinylbenzoate constitutes an interpenetrating network.
[0184] Similarly, irradiation of the 6-7PSil/methacrylic acid
system in the presence of initiator led to increases in the
viscosity, moduli and normal force as a result of the formation of
poly(methyl methacrylate) (that was isolated after the normal
work-up procedure). Thus, the increases in the rheological
properties upon irradiation of both PMMA and PMVPh can be
attributed to establishment of interpenetrating networks as the
monomers are polymerized.
[0185] Representative Syntheses.
[0186] 6-7PSil glutarate (PD3) was synthesized by refluxing and
stirring 3.00 g 6-7PSil, 0.169 g glutaric acid and 5.0 mL methylene
chloride for 3 h in the air. The solvent was removed by placing it
sequentially on a rotary evaporator under dynamic reduced pressure
(150 mm Hg) for >24 h at room temperature, and then under
dynamic reduced pressure of 0.5 mm Hg for 3 h at 40-50.degree.
C.
[0187] IR: 2964, 2905 cm.sup.-1 (C--H), 1563 cm.sup.-1
(C.dbd.O)
[0188] .sup.1H NMR: 6.58-7.88 ppm (br, 6H, .sup.+NH.sub.3), 2.84
ppm (m, 4H, NCH.sub.2), 2.18 ppm (t, 4H, CH.sub.2COO.sup.-), 1.83
ppm (m, 2H, CH.sub.2CCOO.sup.-), 1.73 ppm (m, 4H,
.sup.+NCCH.sub.2), 0.54 ppm (t, 4H, .sup.+NCCCH.sub.2)
[0189] 6-7PSil ammonium acrylate (PMAA) was synthesized by stirring
3.00 g 6-7PSil and 0.184 g acrylic acid at room temperature for 1 h
in air. Methylene chloride (5.0 mL) was added and the mixture was
refluxed and stirred for 3 h. The solvent was removed by placing it
sequentially on a rotary evaporator under dynamic reduced pressure
(150 mm Hg) for >24 h at room temperature, and then under
dynamic reduced pressure of 0.5 mm Hg for 3 h at 40-50.degree.
C.
[0190] IR: 2963, 2905 cm.sup.-1 (C--H), 1635 cm.sup.-1 (C.dbd.C),
1565 cm.sup.-1 (C.dbd.O)
[0191] .sup.1H NMR: 6.70-7.65 ppm (br, 3H, .sup.+NH.sub.3), 6.09
ppm (m, 2H, .dbd.CH.sub.2), 5.52 ppm (t, 1H, .dbd.CH), 2.79 ppm (m,
2H, .sup.+NCH.sub.2), 1.65 ppm (m, 4H, .sup.+NCCH.sub.2), 0.52 ppm
(t, 4H, .sup.+NCCCH.sub.2)
[0192] D.sub.2EDA ammonium acetate was synthesized by stirring 3.00
g D.sub.2EDA and 0.798 g acetic acid at room temperature for 1 h.
Then, the mixture was refluxed and stirred for 3 h in air after
adding 5.0 mL methylene chloride. The solvent was removed by
placing it sequentially on a rotary evaporator, under dynamic
reduced pressure (150 mm Hg) for >24 h at room temperature and
under dynamic reduced pressure of 0.5 mm Hg for 3 h at
40-50.degree. C.
[0193] IR: 2962, 2868 cm.sup.-1 (C--H), 1565 cm.sup.-1
(C.dbd.O)
[0194] .sup.1H NMR: 5.41-5.88 ppm (br, 5H, .sup.+NH.sub.3,
.sup.+NH.sub.2), 3.39 ppm (t, 4H, .sup.+NCCH.sub.2N.sup.+), 3.22
ppm (t, 2H, .sup.+NCH.sub.2CC), 1.65 ppm (m, 2H, .sup.+NCCH.sub.2),
0.46 ppm (t, 2H, .sup.+NCCCH.sub.2)
Example 2
6-7PS Vinylbenzoate and Product of Irradiation
[0195] To further study the reaction of polysiloxane ammonium salts
with acids containing polymerizable olefins upon radiation, 6-7PSil
vinylbenzoate was synthesized using vinylbenzoic acid with the same
procedure with benzoic acid reported above. The .sup.1H NMR
spectrum of this product is shown in FIG. 34, in which it can be
seen that the ammonium salt was synthesized successfully: four
hydrogens at 7.89 and 7.32 are from benzene ring, broad peak from
7.10 to 6.77 ppm is from ammonium salt, three hydrogens at 6.71,
5.77 and 5.30 ppm are from double bond, and six hydrogens at 2.79,
1.64 and 0.45 are from propyl attached to nitrogen.
[0196] From the rheology results it can be seen that the viscosity
and moduli increased after irradiation (FIG. 35 and FIG. 36), which
is similar to vinylbenzoate and methacrylate systems.
[0197] Then hydrolysis of this ammonium salt was performed with the
same procedure as the methacrylate system. The crude product was
mixed with 40 mL 0.25 M NaOH aqueous solution and allowed to stir
for 3 h at 65.degree. C. After vacuum filtration, the liquid was
dried completely to obtain a crude hydrolysis product. During the
extraction a white solid precipitated. After the extraction was
complete, the solid precipitate was separated and dried. The
.sup.1H NMR spectra of the products obtained from hydrolysis
process are shown in FIGS. 37A-D. It can be seen from the spectrum
of solid residue after extraction (FIG. 37E) that there are three
broad peaks at 7.76, 6.67 and 1.69 ppm with integration ratio of
approximately 2:2:3, which can be assigned to the four hydrogens on
the benzene ring and the three hydrogens of the carbon chain of
polyvinylbenzoic acid.
[0198] To further confirm the structure of the solid residue after
extraction obtained from hydrolysis of irradiated 6-7PSil
vinylbenzoate, a sample of polyvinylbenzoic acid was prepared
through free radical solution polymerization. The process is
dissolving 600 mg vinylbenzoic acid and 2 wt % AIBN in 10 g
dioxane, and bubbling nitrogen through solution for 0.5 h, then
stirring the solution for 3 h at 85-90.degree. C. After cooling the
solution to room temperature, it was poured into 200 mL hexane to
obtain a yellow solid followed by washing with chloroform three
times. Finally, the product was dried in a vacuum oven at
50.degree. C. overnight. From the DSC results shown in FIG. 38,
vinylbenzoic acid showed two peaks at 134 and 144.degree. C., which
correspond to its melting point 142-144.degree. C. The product
obtained after the polymerization in solution show nothing in this
area, which means that there is no monomer left. Its .sup.1H NMR
spectrum was identical to that shown in FIG. 37E. These results
confirm that the solid residue is polyvinylbenzoic acid.
Example 3
6-7 PSil Methacrylate and D.sub.2EDA Acrylate
[0199] The 6-7PSil methacrylate was synthesized and investigated,
and it was noted that the viscosity and moduli of 6-7PSil
methacrylate increased greatly after irradiation. A hydrolysis
similar to that in Example 2 was undertaken of the product after
irradiation. The crude product (400 mg) was mixed with 40 mL 0.25 M
NaOH aqueous solution and allowed to stir for 3 h at 65.degree. C.
After vacuum filtration, one half of the liquid was dried
completely to obtain a crude hydrolysis product. Other half part of
this liquid was extracted with 3.times.50 mL ether, methylene
chloride and ethyl acetate separately, then the organic layers were
combined and dried with anhydrous Na.sub.2SO.sub.4 overnight, then
the solvent evaporated and the residue dried in a vacuum oven at
50.degree. C. overnight; the resulting product is termed herein the
first extraction product. The water phase obtained in the first
extraction was neutralized with 1 M HCl in an ice bath to pH 3 then
extracted with same procedure as above to obtain a product termed
herein the second extraction product. For reference, the .sup.1H
NMR spectrum of 6-7PSil methacrylate in CDCl.sub.3 is shown in FIG.
39. In this spectrum, the three proton signals at 6.47 ppm
correspond to the ammonium salt, the two protons at 5.84 and 5.28
ppm are assigned to the hydrogen attached to the double bond, the
three protons at 2.74, 1.62 and 0.50 ppm are assigned to the propyl
group attached to the nitrogen, and the three protons at 1.88 ppm
are assigned to the methyl group of methacrylic acid. The spectrum
of the hydrolysis product (FIG. 40A) reveals the presence of
methacrylic acid due to the signals at 5.42 and 5.11 ppm for the
double bond protons and 1.63 ppm for the methyl group. There does
not appear to be any polymethacrylic acid present. For the first
(FIG. 40B) and second (FIG. 40C) extraction products,
polymethacrylic acid appears to be present because of peaks at 1.26
and 0.89 ppm, corresponding to methylene and methyl protons.
[0200] The viscosity and moduli of 6-7PSil methacrylate increased
after irradiation (FIG. 41 and FIG. 42), similar to the
corresponding acrylate. Also investigated were the viscosity and
moduli for D.sub.2EDA acrylate before and after irradiation (FIG.
43-FIG. 45). This yielded similar results to 6-7PSil acrylate. The
viscosity and moduli of D.sub.2EDA acrylate were higher than that
of D.sub.2EDA, and increased further after irradiation.
EQUIVALENTS
[0201] The invention has been described broadly and generically
herein. Those of ordinary skill in the art will readily envision a
variety of other means and/or structures for performing the
functions and/or obtaining the results and/or one or more of the
advantages described herein, and each of such variations and/or
modifications is deemed to be within the scope of the present
invention. More generally, those skilled in the art will readily
appreciate that all parameters, dimensions, materials, and
configurations described herein are meant to be exemplary and that
the actual parameters, dimensions, materials, and/or configurations
will depend upon the specific application or applications for which
the teachings of the present invention is/are used. Those skilled
in the art will recognize, or be able to ascertain using no more
than routine experimentation, many equivalents to the specific
embodiments of the invention described herein. It is, therefore, to
be understood that the foregoing embodiments are presented by way
of example only and that, within the scope of the appended claims
and equivalents thereto, the invention may be practiced otherwise
than as specifically described and claimed.
* * * * *