U.S. patent application number 16/014114 was filed with the patent office on 2018-11-22 for process for the preparation of defined functional lactic acid oligomers.
The applicant listed for this patent is Total Research & Technology Feluy. Invention is credited to Marion Helou, Martine Slawinski, Jeroen Wassenaar.
Application Number | 20180334535 16/014114 |
Document ID | / |
Family ID | 47358190 |
Filed Date | 2018-11-22 |
United States Patent
Application |
20180334535 |
Kind Code |
A1 |
Slawinski; Martine ; et
al. |
November 22, 2018 |
Process for the Preparation of Defined Functional Lactic Acid
Oligomers
Abstract
A process for manufacturing defined functional lactic acid
oligomers, can include contacting lactide with at least one
compound that is a transfer agent. Oligomers can be prepared
according to the process.
Inventors: |
Slawinski; Martine;
(Nivelles, BE) ; Helou; Marion; (Ixelles, BE)
; Wassenaar; Jeroen; (Bruxelles, BE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Total Research & Technology Feluy |
Seneffe (Feluy) |
|
BE |
|
|
Family ID: |
47358190 |
Appl. No.: |
16/014114 |
Filed: |
June 21, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14364568 |
Jun 11, 2014 |
10030098 |
|
|
PCT/EP2012/075485 |
Dec 14, 2012 |
|
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|
16014114 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 63/08 20130101;
C08G 63/823 20130101; C08G 63/78 20130101 |
International
Class: |
C08G 63/82 20060101
C08G063/82; C08G 63/08 20060101 C08G063/08; C08G 63/78 20060101
C08G063/78 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 15, 2011 |
EP |
11193733.0 |
Claims
1-14. (canceled)
15. A block copolymer comprising: at least one compound, wherein
the compound is a polymer selected from the group consisting of
polypropylene, polyethylene, poly (L) lactic acid, poly (D) lactic
acid, poly (D,L) lactic acid, polysiloxane, polybutylene succinate,
polytrimethylene carbonate, polyester, poly ether, polystyrene,
polyisoprene, polycarbonate, polyalkylenecarbonate, polyvinyl
alcohol, polyurethane, and polyacrylate, wherein each polymer
contains n number of OH and/or NH.sub.2 group(s), wherein n is an
integer greater than or equal to 1, wherein Moles of Lactide (
Moles of Compound * n ) .ltoreq. 70 ; ##EQU00007## and one or more
lactic acid chains, wherein each lactic acid chain is bonded to one
of the polymers, wherein Mn ( lactic acid oligomer ) - Mw (
compound ) n .ltoreq. 10 100 g / mol , ##EQU00008## wherein
Mn(lactic acid chain) is measured by size exclusion chromatography,
and wherein n is the number of OH and NH2 groups present in the
compound, wherein the block copolymer is made by a process
comprising: contacting lactide monomers in the presence of a
catalyst with the at least one compound to form the block copolymer
comprising the lactic acid chain; wherein reaction is performed at
a temperature of at least 70.degree. C.; quenching the reaction so
that the lactic acid chains formed by reaction consist of 70 or
less of the lactide monomers, wherein the quenching agent is an
acid chloride having a formula of Cl--CO--R.sup.9, wherein R.sup.9
is 1-pentenyl or aminoethyl.
16. The block copolymer according to claim 15, wherein said process
is performed without solvent.
17. The block copolymer according to claim 16, wherein said process
is performed at a temperature of 110.degree. C. to 190.degree.
C.
18. The block copolymer according to claim 15, wherein the catalyst
is an organometallic catalyst.
19. The block copolymer according to claim 15, wherein said
catalyst has general formula: M(Y.sup.1, Y.sup.2, . . .
Y.sup.p).sub.q, wherein M is a metal selected from the elements of
columns 3 to 12 of the periodic table of the elements, as well as
the elements Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Ca, Mg and Bi; wherein
Y.sup.1, Y.sup.2, . . . Y.sup.p are each substituents selected from
C.sub.1-20 alkyls, C.sub.6-30 aryls, C.sub.1-20 alkoxys, C.sub.6-30
aryloxys, other oxides, carboxylates, and halide groups as well as
elements of group 15 and/or 16 of the periodic table; wherein p and
q are integers between 1 and 6.
20. The block copolymer according to claim 19, wherein the reaction
is performed at a temperature of at least 140.degree. C.
21. The block copolymer according to claim 15, wherein n is at
least 2.
22. The block copolymer according to claim 15, wherein said
compound is a polymer that is selected from the group consisting
of: polypropylene, polyethylene, poly (L) lactic acid, poly (D)
lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polystyrene, polycarbonate,
polyalkylenecarbonate, polyvinyl alcohol, and polyurethane, wherein
the polymer contains n number of OH and/or NH.sub.2 group(s), and
wherein n is an integer greater than or equal to 1.
23. The block copolymer according to claim 15, wherein the compound
is a polymer selected from the group consisting of: polypropylene,
polyethylene, polysiloxane, polybutylene succinate,
polytrimethylene carbonate, polycarbonate, polyalkylenecarbonate,
polyvinyl alcohol, polyurethane, and polyaminoacid, wherein the
polymer contains n number of OH group(s), and wherein n is an
integer greater than or equal to 1.
Description
FIELD OF THE INVENTION
[0001] The present invention is in the field of processes for the
manufacture of defined functional lactic acid oligomers, in
particular, by contacting lactide with at least one compound that
is a transfer agent. It also relates to oligomers prepared
according to the process.
BACKGROUND OF THE INVENTION
[0002] Lactic acid oligomers are commonly utilised as intermediates
in the synthesis of high molecular weight poly(lactic acid)
products. There is however also a growing interest for lactic acid
oligomers as such. They receive special attention in the field of
medical applications for instance for the production of implantable
medical devices and scaffolds. Because of their intrinsic
properties and their biological-based character they can be also
used in added-value domains such as [0003] a substitute for waxes,
oils and oligomers currently used in the pharmaceutical formulation
domain, [0004] macromers (building blocks) for the polymerisation
or copolymerisation of new and existing polymers, [0005] new
products in such sectors as binding agents, plasticisers,
adhesives, lubricants, inks, nucleating agents, compatibiliser,
etc. where physical and chemical properties are key parameters to
the performance of the material and are achieved by tailoring the
material at molecular scale. Lactic acid oligomers are usually
composed of a few and limited number of lactic acid units and can
be obtained by polycondensation methods: the hydroxyl and
carboxylic acid groups of lactic acid react together and removal of
the water formed during this condensation reaction results in the
formation of longer polymeric chains of lactic acid.
[0006] The main drawback of this process is the occurrence of
numerous competitive reactions resulting in significant amounts of
structurally unclear components. Transesterification reactions,
both inter and intramolecular, can occur during the
polycondensation. Impurities such as carboxylic acids (e.g. formic
acid, acetic acid, propionic acid etc . . . ) or alcohols (e.g.
methanol, ethanol, propanol etc . . . ) in the monomer (lactic
acid) can act as chain terminators. Therefore, polymers of
different sizes with linear, branched or ring structures might be
formed.
[0007] The polycondensation of lactic acid is a step-growth
reaction that results in carboxylic acid and alcoholic end-groups
(di-end-functional polymers). Without further modification of the
end-groups, the use of PLA oligomers as building blocks is
therefore limited. For example telechelic PLA-diol receives a
growing interest for the production of copolymers (amongst other
with polyethylene glycol or with diisocyanate to form
polyurethanes) cannot be produced directly by polycondensation.
[0008] The present invention aims to overcome the problems of the
art be providing a new technique for producing well-defined
functional lactic acid oligomers from lactide.
SUMMARY OF THE INVENTION
[0009] The present invention relates to a process for the
manufacture of a lactic acid oligomer comprising the steps of:
contacting lactide in the presence of a catalyst with at least one
compound, wherein said compound is a polymer selected from the
group comprising of polypropylene, polyethylene, poly (L) lactic
acid, poly (D) lactic acid, poly (D,L) lactic acid, polysiloxane,
polybutylene succinate, polytrimethylene carbonate,
polycaprolactone, polyester, polyether, polyolefin, polystyrene,
polyisoprene, polycarbonate, polyalkylenecarbonate, polyamine,
polyamide, polyvinyl alcohol, polyurethane, and polyacrylate, and
containing n number of OH and/or NH.sub.2 group(s), where n is an
integer greater than or equal to 1, and wherein
Moles of Lactide ( Moles of Compound * n ) .ltoreq. 70 ,
##EQU00001##
[0010] and wherein the reaction is performed at a temperature of at
least 70.degree. C.
[0011] The process may be performed with or without solvent.
[0012] The catalyst employed by the process may have general
formula M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q, in which M is a
metal selected from the group comprising the elements of columns 3
to 12 of the periodic table of the elements, as well as the
elements Al, Ga, In, Tl, Ge, Sn, Pb, Sb, Ca, Mg and Bi; whereas
Y.sup.1, Y.sup.2, . . . Y.sup.p are each substituents selected from
the group comprising alkyl with 1 to 20 carbon atoms, aryl having
from 6 to 30 carbon atoms, alkoxy having from 1 to 20 carbon atoms,
aryloxy having from 6 to 30 carbon atoms, and other oxide,
carbon/late, and halide groups as well as elements of group 15
and/or 16 of the periodic table; p and q are integers between 1 and
6.
[0013] The catalyst may have a general formula (III):
##STR00001##
[0014] wherein
[0015] R.sup.2 and R.sup.3 are each independently
C.sub.1-10alkyl,
[0016] R.sup.4, R.sup.5 and R.sup.6 are each independently
C.sub.1-10alkyl, or
[0017] R.sup.4 and R.sup.5 are covalently bound to each other and
are each a methylene and
[0018] R.sup.6 is C.sub.1-10alkyl,
[0019] X.sup.2 is selected from C.sub.1-10alkyl, --OR.sup.7, or
--N(SiR.sup.8.sub.3).sub.2, R.sup.7 is C.sub.1-10alkyl, and R.sup.8
is C.sub.1-6alkyl.
[0020] X.sup.1 may be NH.sub.2. X.sup.1 may be OH. n may be at
least 2
[0021] R.sup.1 wherein may be selected from ethyl, propyl,
prop-2-yl, or octyl. R.sup.1 may be propyl and n is 1,or R.sup.1
may be prop-2-yl and n is 3, or R.sup.1 may be ethyl and n is
2.
[0022] R.sup.1 may be selected from prop-2-enecarbonyloxyethyl,
prop-2-enecarbonyloxypropyl, prop-2-enecarbonyloxymethyl,
ethylenecarbonyloxymethyl, ethylenecarbonyloxyethyl, or
ethylenecarbonyloxypropyl.
[0023] R.sup.1 may be selected from
C.sub.6-C.sub.8arylC.sub.1-C.sub.4alkyl,
C.sub.6-C.sub.8arylC.sub.1-C.sub.2alkyl or benzyl.
[0024] The number average molecular weight of the lactic acid
oligomer as measured by size exclusion chromatography minus the
molecular weight the compound divided by n may be equal to or below
10 100 g/mol,
Mn ( lactic acid oligomer ) - Mw ( compound ) n .ltoreq. 10 100 g /
mol , ##EQU00002##
[0025] wherein Mn(lactic acid oligomer) is measured by size
exclusion chromatography, and wherein n is number of OH and NH2
groups present in the compound.
[0026] The at least one compound may be a mixture of at least two
of the polymers.
[0027] The invention also relates to an oligomer prepared according
to the process of the invention.
DESCRIPTION OF THE FIGURES
[0028] FIG. 1 is a presentation of the DSC curve for PP/PLA blend
(50/50).
[0029] FIG. 2 is a presentation of the DSC curve PP/PLA/PP-PLA
blend (40/40/10).
[0030] FIG. 3 is a presentation of the SEM picture of blend PP/PLA
50/50.
[0031] FIG. 4 is a presentation of the SEM picture of blend
PP/PLA/PP-PLA 40/40/10.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Unless otherwise defined, all terms used in disclosing the
invention, including technical and scientific terms, have the
meaning as commonly understood by one of ordinary skill in the art
to which this invention belongs. By means of further guidance, term
definitions are included below to better appreciate the teaching of
the present invention.
[0033] Before the present process or products of the invention is
described, it is to be understood that this invention is not
limited to particular processes or products described, as such
processes or products may, of course, vary. It is also to be
understood that the terminology used herein is not intended to be
limiting, since the scope of the present invention will be limited
only by the appended claims.
[0034] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
appearances of the phrases "in one embodiment" or "in an
embodiment" in various places throughout this specification are not
necessarily all referring to the same embodiment, but may.
Furthermore, the particular features, structures or characteristics
may be combined in any suitable manner, as would be apparent to a
person skilled in the art from this disclosure, in one or more
embodiments. Furthermore, while some embodiments described herein
include some but not other features included in other embodiments,
combinations of features of different embodiments are meant to be
within the scope of the invention, and form different embodiments,
as would be understood by those in the art. For example, in the
following claims, any of the claimed embodiments can be used in any
combination.
[0035] As used herein, the singular forms "a", "an", and "the"
include both singular and plural referents unless the context
clearly dictates otherwise.
[0036] The terms "comprising", "comprises" and "comprised of" as
used herein are synonymous with "including", "includes" or
"containing", "contains", and are inclusive or open-ended and do
not exclude additional, non-recited members, elements or method
steps. Where reference is made to embodiments as comprising certain
elements or steps, this implies that embodiments are also envisaged
which consist essentially of the recited elements or steps.
[0037] The recitation of numerical ranges by endpoints includes all
numbers and fractions subsumed within the respective ranges, as
well as the recited endpoints.
[0038] All documents cited in the present specification are hereby
incorporated by reference in their entirety.
[0039] The present invention discloses a process for obtaining
well-defined lactic acid oligomers in terms of molecular weight
control, chain end control and structure control. Structure control
refers to the linearity or branching, and sequence distribution in
the case of copolymers.
[0040] In particular the present invention provides a process for
the manufacture of a lactic acid oligomer comprising the steps of:
contacting lactide in the presence of a catalyst with at least one
compound, wherein said compound is a polymer selected from the
group comprising of polypropylene, polyethylene, poly (L) lactic
acid, poly (D) lactic acid, poly (D,L) lactic acid, polysiloxane,
polybutylene succinate, polytrimethylene carbonate,
polycaprolactone, polyester, polyether, polyolefin, polystyrene,
polycarbonate, polyalkylenecarbonate, polyamine, polyamide,
polyvinyl alcohol, polyurethane, and polyacrylate, and containing n
number of OH and/or NH.sub.2 group(s), where n is an integer
greater than or equal to 1, and wherein
Moles of Lactide ( Moles of Compound * n ) .ltoreq. 70 ,
##EQU00003##
[0041] and wherein the reaction is performed at a temperature of at
least 70.degree. C.
[0042] By the term at least one compound is meant one or more
compound(s) selected from the defined list of compounds. A compound
according to one aspect of the present invention is a polymer. The
at least one compound can be a mixture of at least two of the
polymers selected from the defined list of polymers. Therefore, if
more than one compound (polymer) is used, it is meant that
compounds are different compounds (different polymers), and
selected from the defined list of compounds (polymers).
[0043] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polyolefin, polystyrene,
polycarbonate, polyalkylenecarbonate, polyvinyl alcohol,
polyurethane, and polyacrylate, and containing n number of OH
and/or NH.sub.2 group(s), where n is an integer greater than or
equal to 1.
[0044] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising of polypropylene, polyethylene, poly (L) lactic acid,
poly (D) lactic acid, poly (D,L) lactic acid, polysiloxane,
polybutylene succinate, polytrimethylene carbonate, polystyrene,
polycarbonate, polyalkylenecarbonate, polyvinyl alcohol,
polyurethane, and polyacrylate, and containing n number of OH
and/or NH.sub.2 group(s), where n is an integer greater than or
equal to 1.
[0045] In an embodiment a compound used in the process according to
the present invention may be a polymer that is polypropylene
containing n number of OH and/or NH.sub.2 group(s), where n is an
integer greater than or equal to 1. The polymer may be
polypropylene containing n number of OH groups, where n is an
integer greater than or equal to 1. The reaction may be performed
in solvent. The reaction may be performed at a temperature of
90.degree. C. -120.degree. C.
[0046] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising of polypropylene, polyethylene, poly (L) lactic acid,
poly (D) lactic acid, poly (D,L) lactic acid, polysiloxane,
polybutylene succinate, polytrimethylene carbonate, polyolefin,
polystyrene, polycarbonate, polyalkylenecarbonate, polyvinyl
alcohol, polyurethane, and polyacrylate, and containing n number of
OH and/or NH.sub.2 group(s), where n is an integer greater than or
equal to 1, and the reaction is performed with solvent at a
temperature of at least 90.degree. C., preferably 90-120.degree. C.
using a catalyst of the general formula M(Y.sup.1,Y.sup.2, . . .
Y.sup.p).sub.q.
[0047] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising of polypropylene, polyethylene, poly (L) lactic acid,
poly (D) lactic acid, poly (D,L) lactic acid, polysiloxane,
polybutylene succinate, polytrimethylene carbonate, polyolefin,
polystyrene, polycarbonate, polyalkylenecarbonate, polyvinyl
alcohol, polyurethane, and polyacrylate, and containing n number of
OH and/or NH.sub.2 group(s), where n is an integer greater than or
equal to 1, and the reaction is performed without solvent at a
temperature of at least 110.degree. C., preferably 140.degree.
C.-190.degree. C. using a catalyst of the general formula
M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q.
[0048] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising of polypropylene, polyethylene, poly (L) lactic acid,
poly (D) lactic acid, poly (D,L) lactic acid, polysiloxane,
polybutylene succinate, polytrimethylene carbonate, polyolefin,
polystyrene, polycarbonate, polyalkylenecarbonate, polyvinyl
alcohol, polyurethane, and polyacrylate, and containing n number of
OH and/or NH.sub.2 group(s), where n is an integer greater than or
equal to 1, and the reaction is performed with solvent at a
temperature of at least 70.degree. C., preferably 90-120.degree. C.
using a catalyst of the general formula (III).
[0049] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising of polypropylene, polyethylene, poly (L) lactic acid,
poly (D) lactic acid, poly (D,L) lactic acid, polysiloxane,
polybutylene succinate, polytrimethylene carbonate, polyolefin,
polystyrene, polycarbonate, polyalkylenecarbonate, polyvinyl
alcohol, polyurethane, and polyacrylate, and containing n number of
OH and/or NH.sub.2 group(s), where n is an integer greater than or
equal to 1, and the reaction is performed without solvent at a
temperature of at least 110.degree. C., preferably at least
140.degree. C., preferably 140.degree. C.-190.degree. C. using a
catalyst of the general formula (III).
[0050] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polyolefin, polystyrene,
polycarbonate, polyalkylenecarbonate, polyamine, polyamide,
polyvinyl alcohol, polyurethane, polyacrylate and polyaminoacid,
and containing n number of OH group(s), where n is an integer
greater than or equal to 1, and the reaction is performed with or
without solvent at a temperature of at least 140.degree. C. and
using a organometallic catalyst or a catalyst of the general
formula M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q.
[0051] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polycaprolactone, polyester,
polyether, polyolefin, polystyrene, polyisoprene, polycarbonate,
polyalkylenecarbonate, polyamine, polyamide, polyvinyl alcohol,
polyurethane, polyacrylate and polyaminoacid, and containing n
number of NH.sub.2 group(s), where n is an integer greater than or
equal to 1, and the reaction is performed with or without solvent
at a temperature of at least 140.degree. C. and using a
organometallic catalyst or a calatyst of the general formula
M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q.
[0052] In an embodiment a a compound used in the process according
to the present invention may be a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polycaprolactone, polyester,
polyether, polyolefin, polystyrene, polyisoprene, polycarbonate,
polyalkylenecarbonate, polyamine, polyamide, polyvinyl alcohol,
polyurethane, polyacrylate and polyaminoacid, and containing n
number of NH.sub.2 and OH group(s), where n is an integer greater
than or equal to 2 and the reaction is performed with or without
solvent at a temperature of at least 140.degree. C. and using a
organometallic catalyst or a calatyst of the general formula
M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q.
[0053] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polyolefin, polystyrene,
polycarbonate, polyalkylenecarbonate, polyamine, polyamide,
polyvinyl alcohol, polyurethane, polyacrylate and polyaminoacid,
and containing n number of OH group(s), where n is an integer
greater than or equal to 1, and the reaction is performed with or
without solvent at a temperature of at least 110.degree. C. and
using a organometallic catalyst or using a catalyst the general
formula (III).
[0054] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polycaprolactone, polyester,
polyether, polyolefin, polystyrene, polyisoprene, polycarbonate,
polyalkylenecarbonate, polyamine, polyamide, polyvinyl alcohol,
polyurethane, polyacrylate and polyaminoacid, and containing n
number of NH.sub.2 group(s), where n is an integer greater than or
equal to 1, and the reaction is performed with or without solvent
at a temperature of at least 110.degree. C. and using a
organometallic catalyst or using a catalyst the general formula
(III).
[0055] In an embodiment a compound used in the process according to
the present invention may be a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polycaprolactone, polyester,
polyether, polyolefin, polystyrene, polyisoprene, polycarbonate,
polyalkylenecarbonate, polyamine, polyamide, polyvinyl alcohol,
polyurethane, polyacrylate and polyaminoacid, and containing n
number of NH.sub.2 and OH group(s), where n is an integer greater
than or equal to 2 and the reaction is performed with or without
solvent at a temperature of at least 110.degree. C. and using a
organometallic catalyst or using a catalyst the general formula
(III).
[0056] In particular, the present invention provides a process for
the manufacture of a lactic acid oligomer comprising the step of
contacting lactide with at least one compound that is a transfer
agent, in the presence of a catalyst wherein the mole ratio of
lactide to (compound.n) is equal to or below 70, wherein compound.n
refers to the moles of compound multiplied by the total number (n)
of OH and/or NH.sub.2 groups in the compound, wherein the reaction
is performed at a temperature of 110.degree. C. to 190.degree. C.
without solvent, wherein the compound is a polymer selected from
the group comprising polyolefin, polyester, polycarbonate,
polypropylene, polyethylene, poly (L) lactic acid, poly (D) lactic
acid, poly (D,L) lactic acid, polybutylene succinate,
polytrimethylene carbonate, polyalkylenecarbonate, polysiloxane,
polyether, polystyrene, polyisoprene, polyamine, polyamide,
polyvinyl alcohol, polyurethane, polyacrylate and polyaminoacid,
and containing n number of OH and/or NH.sub.2 group(s), where n is
an integer greater than or equal to 1. The product may be referred
to as a co-polymer of the lactide monomer and the polymer.
[0057] The present invention also provides a process for the
manufacture of a lactic acid oligomer comprising the step of
contacting lactide with at least one compound that is a transfer
agent, in the presence of a catalyst wherein the mole ratio of
lactide to compound.n is equal to or below 70, wherein compound.n
refers to the number of moles of compound multiplied by the total
number of OH and/or NH.sub.2 groups in the compound, and wherein
the reaction is performed at a temperature of at least 70.degree.
C., preferably at least 90.degree. C., preferably at least
105.degree. C., wherein the compound has formula (I)
##STR00002##
[0058] wherein X.sup.1 is OH or NH.sub.2, n is an integer selected
from 1, 2, 4, 5, 6, 7, 8, 9,or 10 or is 1 to 10, and R.sup.1 is a
group selected from C.sub.1-C.sub.20alkyl;
C.sub.3-C.sub.8cycloalkyl; C.sub.2-C.sub.20alkenyl;
C.sub.2-C.sub.20alkynyl;
C.sub.2-C.sub.10alkenylcarbonyloxyC.sub.1-C.sub.10alkyl;
heterocycylC.sub.1-C.sub.6alkyl;
hydroxylcarbonylC.sub.1-C.sub.100alkyl;
C.sub.6-C.sub.10arylC.sub.1-C.sub.6alkyloxycarbonylaminoC.sub.1-C.sub.10a-
lkyl; aminoC.sub.1-C.sub.10alkyl;
haloC.sub.1-C.sub.10alkylcarbonyloxyC.sub.1-C.sub.10alkyl;
hydroxyC.sub.1-C.sub.10alkyl; heterocycyl;
C.sub.6-C.sub.10arylC.sub.1-C.sub.6alkyl; each group being
optionally substituted by one or more substituents selected from
C.sub.1-C.sub.6alkyl, hydroxyl, oxo, or wherein said at least one
carbon atom in the heterocyclyl is optionally substituted by one or
more oxo group, or wherein at least one nitrogen atom in the
heterocyclyl is optionally substituted by an oxyl free radical.
[0059] The term "alkyl" by itself or as part of another
substituent, refers to a straight or branched saturated hydrocarbon
group joined by single carbon-carbon bonds having 1 to 100 carbon
atoms, for example 1 to 20 carbon atoms, for example 1 to 6 carbon
atoms, preferably 1 to 3 carbon atoms. When a subscript is used
herein following a carbon atom, the subscript refers to the number
of carbon atoms that the named group may contain.
[0060] Thus, for example, C.sub.1-100alkyl, means an alkyl group of
1 to 100 carbon atoms, for example 1 to 75 carbon atoms, for
example 1 to 50 carbon atoms, for example 1 to 25 carbon atoms, for
example 1 to 20 carbon atoms, for example 1 to 10 carbon atoms,
more preferably 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20 carbon atoms.
[0061] Thus, for example, C.sub.1-25alkyl, means an alkyl group of
1 to 25 carbon atoms, preferably from 3 to 15 carbon atoms, more
preferably 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20, 21, 22, 23, 24, 25 carbon atoms.
[0062] Thus, for example, C.sub.1-20alkyl, means an alkyl group of
1 to 20 carbon atoms, preferably from 3 to 15 carbon atoms, more
preferably 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20 carbon atoms.
[0063] Thus, for example, C.sub.1-15alkyl, means an alkyl group of
1 to 15 carbon atoms, preferably from 3 to 15 carbon atoms, more
preferably 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 carbon
atoms.
[0064] Thus, for example, C.sub.1-10alkyl, means an alkyl group of
1 to 10 carbon atoms, preferably from 3 to 10 carbon atoms, more
preferably 3, 4, 5, 6, 7, 8, 9, 10 carbon atoms.
[0065] Thus, for example, C.sub.1-8alkyl, means an alkyl group of 1
to 8 carbon atoms, preferably from 3 to 8 carbon atoms, more
preferably 3, 4, 5, 6, 7, 8 carbon atoms.
[0066] Thus, for example, C.sub.1-6alkyl means an alkyl of 1 to 6
carbon atoms, preferably from 2 to 6 carbon atoms, more preferably
2, 3, 4, 5, 6 carbon atoms.
[0067] Thus, for example, C.sub.1-4alkyl means an alkyl of 1 to 4
carbon atoms, preferably from 2 to 4 carbon atoms, more preferably
2, 3 or 4 carbon atoms.
[0068] Alkyl groups may be linear, or branched and may be
substituted as indicated herein.
[0069] Alkyl includes all linear, or branched alkyl groups. Alkyl
includes, for example, methyl, ethyl, n-propyl, i-propyl,
2-methyl-ethyl, butyl and its isomers (e.g. n-butyl, i-butyl and
t-butyl); pentyl and its isomers, hexyl and its isomers, heptyl and
its isomers, octyl and its isomers, nonyl and its isomers, decyl
and its isomers and the like.
[0070] The term "C.sub.3-8cycloalkyl", by itself or as part of
another substituent, refers to a saturated or partially saturated
cyclic alkyl containing from about 3 to about 8 carbon atoms.
Examples of monocyclic C.sub.3-8cycloalkyl include cyclopropyl,
cyclobutyl, cyclopentyl, or cyclohexyl.
[0071] Whenever the term "substituted" is used in the present
invention, it is meant to indicate that one or more hydrogens on
the atom indicated in the expression using "substituted" is
replaced with a selection from the indicated group, provided that
the indicated atom's normal valency is not exceeded, and that the
substitution results in a chemically stable substance, i.e. a
substance that is sufficiently robust to survive isolation to a
useful degree of purity from a reaction mixture.
[0072] The term "alkenyl" by itself or as part of another
substituent, refers to an unsaturated hydrocarbyl group, which may
be linear, or branched, comprising one or more carbon-carbon double
bonds having 2 to 20 carbon atoms, for example 2 to 18 carbon
atoms, for example 2 to 16 carbon atoms, for example 2 to 15 carbon
atoms, for example 2 to 14 carbon atoms, for example 2 to 12 carbon
atoms, for example 2 to 10 carbon atoms, for example 2 to 8 carbon
atoms, for example 2 to 6 carbon atoms, for example 2 to 4 carbon
atoms. When a subscript is used herein following a carbon atom, the
subscript refers to the number of carbon atoms that the named group
may contain.
[0073] Thus, for example, C.sub.2-20alkenyl means an alkenyl group
of 2 to 20 carbon atoms, preferably 2 and 14 carbon atoms. Thus,
for example, C.sub.2-18alkenyl means an alkenyl group of 2 to 18
carbon atoms, preferably 2 to 12 carbon atoms. Thus, for example,
C.sub.2-16alkenyl means an alkenyl group of 2 to 16 carbon atoms,
preferably 2 to 10 carbon atoms. Thus, for example,
C.sub.2-15alkenyl means an alkenyl group of 2 to 15 carbon atoms,
preferably 2 to 10 carbon atoms. Thus, for example,
C.sub.2-14alkenyl means an alkenyl group of 2 to 14 carbon atoms,
preferably 2 to 10 carbon atoms. Thus, for example,
C.sub.2-12alkenyl means an alkenyl group of 2 to 12 carbon atoms,
preferably 2 to 8 carbon atoms. Thus, for example,
C.sub.2-10alkenyl means an alkenyl group of 2 to 10 carbon atoms,
preferably 2 to 6 carbon atoms. Thus, for example, C.sub.2-8alkenyl
means an alkenyl group of 2 to 8 carbon atoms, preferably 2 to 6
carbon atoms. Thus, for example, C.sub.2-6alkenyl means an alkenyl
group of 2 to 6 carbon atoms, preferably 2 to 5 carbon atoms. Thus,
for example, C.sub.2-4alkenyl means an alkenyl group of 2 to 4
carbon atoms, preferably 2 or 3 carbon atoms. Non-limiting examples
of alkenyl groups include ethenyl, 2-propenyl, 2-butenyl,
3-butenyl, 2-pentenyl and its chain isomers, 2-hexenyl and its
chain isomers, 2,4-pentadienyl and the like.
[0074] The term "C.sub.2-20alkynyl" by itself or as part of another
substituent, refers to an unsaturated hydrocarbyl group, which may
be linear, or branched, comprising one or more carbon-carbon triple
bonds. When a subscript is used herein following a carbon atom, the
subscript refers to the number of carbon atoms that the named group
may contain.
[0075] Preferred alkynyl groups thus comprise 2 to 20 carbon atoms,
for example, 2 to 14 carbon atoms, for example 2 to 8. Non limiting
examples of alkynyl groups include ethynyl, 2-propynyl, 2-butynyl,
3-butynyl, 2-pentynyl and its chain isomers, 2-hexynyl and its
chain isomers and the like.
[0076] The term "aryl", as a group or part of another substituent,
refers to a polyunsaturated, aromatic hydrocarbyl group having a
single ring (i.e. phenyl) or multiple aromatic rings fused together
(e.g. naphthalene), or linked covalently, typically containing 6 to
30 atoms; wherein at least one ring is aromatic. When a subscript
is used herein following a carbon atom, the subscript refers to the
number of carbon atoms that the named group may contain. Thus, for
example, C.sub.6-30aryl means an aryl group of 6 to 30 carbon
atoms, preferably 6 to 20 carbon atoms. Thus, for example,
C.sub.6-12aryl means an aryl group of 6 to 12 carbon atoms,
preferably 6 to 10 carbon atoms. Thus, for example, C.sub.6-10aryl
means an aryl group of 6 to 10 carbon atoms, preferably 6 to 8
carbon atoms. Thus, for example, C.sub.6-8aryl means an aryl group
of 6 to 8 carbon atoms. Thus, for example, C.sub.6-7aryl means an
aryl group of 6 to 7 carbon atoms. Non-limiting examples of an aryl
comprise phenyl, biphenylyl, biphenylenyl, or 1-or
2-naphthanelyl.
[0077] The term "C.sub.6-10arylC.sub.1-6alkyl", as a group or as
part of another substituent, means a C.sub.1-- 6alkyl as defined
herein, wherein a hydrogen atom is replaced by a C.sub.6-10aryl as
defined herein. Examples of aralkyl include benzyl, phenethyl,
dibenzylmethyl, methylphenylmethyl, 3-(2-naphthyl)-butyl, and the
like.
[0078] The term "hydroxyC.sub.1-10alkyl", by itself or as part of
another substituent, represents a group of Formula --R.sup.e--OH,
wherein Re is C.sub.1-10alkyl.
[0079] The term "alkoxy" or "alkyloxy" as used herein refers to a
group having the formula --OR.sup.d wherein R.sup.d is alkyl. For
instance, the term "C.sub.1-20alkoxy" or "C.sub.1-20alkyloxy"
refers to a group having the formula --OR.sup.d wherein R.sup.d is
C.sub.1-20alkyl For instance,the "C.sub.1-6alkoxy" or
"C.sub.1-6alkyloxy" refers to a group having the formula --OR.sup.d
wherein R.sup.d is C.sub.1-6alkyl. Non-limiting examples of
suitable alkoxy include methoxy, ethoxy, propoxy, isopropoxy,
butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy and
hexyloxy.
[0080] The terms "heterocyclyl" or "heterocyclo" as used herein by
itself or as part of another substituent refer to non-aromatic,
fully saturated or partially unsaturated cyclic groups (for
example, 3 to 13 member monocyclic, 7 to 17 member bicyclic, or 10
to 20 member tricyclic ring systems, or containing a total of 3 to
10 ring atoms) which have at least one heteroatom in at least one
carbon atom-containing ring. Each ring of the heterocyclic group
containing a heteroatom may have 1, 2, 3 or 4 heteroatoms selected
from nitrogen atoms, oxygen atoms and/or sulfur atoms, where the
nitrogen and sulfur heteroatoms may optionally be oxidized and the
nitrogen heteroatoms may optionally be quaternised. The
heterocyclic group may be attached at any heteroatom or carbon atom
of the ring or ring system, where valence allows. The rings of
multi-ring heterocycles may be fused, bridged and/or joined through
one or more spiro atoms. An optionally substituted heterocyclic
refers to a heterocyclic having optionally one or more substituents
(for example 1 to 4 substituents, or for example 1, 2, 3 or 4),
selected from those defined above for substituted aryl.
[0081] Exemplary heterocyclic groups include piperidinyl,
azetidinyl, imidazolinyl, imidazolidinyl, isoxazolinyl,
oxazolidinyl, isoxazolidinyl, thiazolidinyl, isothiazolidinyl,
piperidyl, succinimidyl, 3H-indolyl, isoindolinyl, chromenyl,
isochromanyl, xanthenyl, 2H-pyrrolyl, 1-pyrrolinyl, 2-pyrrolinyl,
3-pyrrolinyl, pyrrolidinyl, 4H-quinolizinyl, 4aH-carbazolyl,
2-oxopiperazinyl, piperazinyl, homopiperazinyl, 2-pyrazolinyl,
3-pyrazolinyl, pyranyl, dihydro-2H-pyranyl, 4H-pyranyl,
3,4-dihydro-2H-pyranyl, phthalazinyl, oxetanyl, thietanyl,
3-dioxolanyl, 1,4-dioxanyl, 2,5-dioximidazolidinyl,
2,2,4-piperidonyl, 2-oxopiperidinyl, 2-oxopyrrolodinyl,
2-oxoazepinyl, indolinyl, tetrahydropyranyl, tetrahydrofuranyl,
tetrehydrothienyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl,
thiomorpholinyl, thiomorpholinyl sulfoxide, thiomorpholinyl
sulfone, 1,3-dioxolanyl, 1,4-oxathianyl, 1,4-dithianyl,
1,3,5-trioxanyl, 6H-1,2,5-thiadiazinyl, 2H-1,5,2-dithiazinyl,
2H-oxocinyl, 1H-pyrrolizinyl, tetrahydro-1,1-dioxothienyl, N-
formylpiperazinyl, and morpholinyl.
[0082] The term "oxo" as used herein refers to the group
.dbd.O.
[0083] The term "halo" as used herein refers to a halogen group,
for example, fluorine (F), chlorine (Cl), bromine (Br), or iodine
(I).
[0084] The term "alkylcarbonyloxy" by itself or as part of another
substituent refers to a --O--C(.dbd.O)R.sup.e wherein R.sup.e is as
defined above for alkyl.
[0085] The term "alkenylcarbonyloxy" by itself or as part of
another substituent refers to a --O--C(.dbd.O)R.sup.f wherein
R.sup.f is as defined above for alkenyl.
[0086] The term "alkoxycarbonyl" by itself or as part of another
substituent refers to a carboxy group linked to an alkyl i.e. to
form --C(.dbd.O)OR.sup.e, wherein R.sup.e is as defined above for
alkyl.
[0087] The term "hydroxylcarbonyl" by itself or as part of another
substituent refers to a hydroxyl group linked to a carbonyl group
i.e. to form HO--(C.dbd.O)--.
[0088] The term "aryloxy" by itself or as part of another
substituent refers to a group having the formula --OR.sup.a wherein
R.sup.a is aryl as defined herein. For instance, C.sub.6-30aryloxy
refers to a group having the formula --OR.sup.a wherein R.sup.a is
C.sub.6-30aryl as defined herein. For instance, C.sub.6-12aryloxy
refers to a group having the formula --OR.sup.a wherein R.sup.a is
C.sub.6-12aryl as defined herein. Non-limiting examples of suitable
C.sub.6-12aryl include phenoxy, 2-naphthoxy and 1-naphthoxy.
[0089] In an embodiment, the compound has formula (I) and R.sup.1
is a group selected from C.sub.1-C.sub.15alkyl;
C.sub.3-8cycloalkyl; C.sub.2-C.sub.15alkenyl;
C.sub.2-C.sub.15alkynyl;
C.sub.2-C.sub.8alkenylcarbonyloxyC.sub.1-C.sub.8alkyl;
heterocycylC.sub.1-C.sub.4alkyl;
hydroxylcarbonylC.sub.1-C.sub.50alkyl;
C.sub.6-C8arylC.sub.1-C.sub.4alkyloxycarbonylaminoC.sub.1-C.sub.8alkyl;
aminoC.sub.1-C.sub.8alkyl;
haloC.sub.1-C.sub.8alkylcarbonyloxyC.sub.1-C .sub.8alkyl;
hydroxyC.sub.1-C.sub.8alkyl; heterocycyl;
C.sub.6-C.sub.8arylC.sub.1-C.sub.4alkyl; each group being
optionally substituted by one or more substituents selected from
C.sub.1-C.sub.6alkyl, hydroxyl, oxo, or wherein said at least one
carbon atom in the heterocyclyl is optionally substituted by one or
more oxo group, or wherein at least one nitrogen atom in the
heterocyclyl is optionally substituted by an oxyl free radical;
[0090] or the compound is a polymer selected from the group
comprising polyolefin, polyester, polycarbonate, polypropylene,
polyethylene, poly (L) lactic acid, poly (D) lactic acid, poly
(D,L) lactic acid, polybutylene succinate, polycaprolactone,
polytrimethylene carbonate, polyalkylenecarbonate, polysiloxane,
polyether, polystyrene, polyisoprene, polyamine, polyamide,
polyvinyl alcohol, polyurethane, polyacrylate and polyaminoacid,
and containing n OH and/or NH.sub.2 group, where n is an integer
greater than or equal to 1.
[0091] In an embodiment, the compound has formula (I) and R.sup.1
is a group selected from C.sub.1-C.sub.10alkyl;
C.sub.3-8cycloalkyl; C.sub.2-C.sub.10alkenyl;
C.sub.2C.sub.10alkynyl;
C.sub.2-C.sub.4alkenylcarbonyloxyC.sub.1-C.sub.6alkyl;
heterocycylC.sub.1-C.sub.4alkyl;
hydroxylcarbonylC.sub.1-C.sub.25alkyl;
C.sub.6-C.sub.7arylC.sub.1-C.sub.3alkyloxycarbonylamino
C.sub.1-C.sub.6 alkyl; aminoC.sub.1-C.sub.6alkyl;
haloC.sub.1-C.sub.6alkylcarbonyloxyC.sub.1-C.sub.6alkyl;
hydroxyC.sub.1-C.sub.6alkyl; heterocycyl;
C.sub.6-C.sub.8arylC.sub.1-C.sub.2alkyl;; each group being
optionally substituted by one or more substituents selected from
C.sub.1-C.sub.4alkyl, hydroxyl, oxo, or wherein said at least one
carbon atom in the heterocyclyl is optionally substituted by one or
more oxo group, or wherein at least one nitrogen atom in the
heterocycly is optionally substituted by an oxyl free radical,
[0092] or
[0093] the compound is a polymer selected from the group comprising
polyolefin, polyester, polycarbonate, polypropylene, polyethylene,
poly (L) lactic acid, poly (D) lactic acid, poly (D,L) lactic acid,
polybutylene succinate, polycaprolactone, polytrimethylene
carbonate, polyalkylenecarbonate, polysiloxane, polyether,
polystyrene, polyisoprene, polyamine, polyamide, polyvinyl alcohol,
polyurethane, polyacrylate and polyaminoacid, and containing n OH
and/or NH.sub.2 group, where n is an integer greater than or equal
to 1.
[0094] The process employs ring-opening oligomerisation of lactide
in the presence of a transfer agent that is the compound of formula
(I). Oligomerisation is performed in the presence of a catalyst,
which is preferably a metal catalyst. Oligomerisation can performed
using a technique of melt polymerization (bulk) or in solvent.
Oligomerisation can be performed in one pot reactor.
[0095] Oligomerisation can be performed at a temperature of
70.degree. C.-190.degree. C. Preferably, the reaction is performed
at a temperature of greater than 105.degree. C., 106.degree. C.,
107.degree. C., 108.degree. C., 109.degree. C., or 110.degree. C.
The temperature is preferably that of the reaction itself.
According to an embodiment, the oligomerisation can be performed at
a temperature of at least 110.degree. C. when the catalyst has
general formula III. According to an embodiment, the
oligomerisation can be performed at a temperature of at least
140.degree. C. when the catalyst has general formula
M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q. According to an
embodiment, without solvent, oligomerisation can be performed at a
temperature of 110.degree. C.-190.degree. C. in bulk. According to
an embodiment, with solvent, oligomerisation can be performed at a
temperature of 90.degree. C.-120.degree. C. According to an
embodiment, without solvent, oligomerisation can be performed at a
temperature of 140-190.degree. C. in bulk when the catalyst has
general formula M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q. According
to an embodiment, with solvent, oligomerisation can be performed at
a temperature of 90.degree. C.-120.degree. C. when the catalyst has
general formula M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q. According
to an embodiment, without solvent, oligomerisation can be performed
at a temperature of 110-190.degree. C. in bulk when the catalyst
has general formula (III). According to an embodiment, with
solvent, oligomerisation can be performed at a temperature of
-90-120.degree. C. when the catalyst has general formula (III).
[0096] In an embodiment, R.sup.1 is a group selected from
C.sub.1-C.sub.20alkyl; C.sub.3-8cycloalkyl;
C.sub.2-C.sub.20alkenyl; C.sub.2-C.sub.20alkynyl;
C.sub.2-C.sub.10alkenylcarbonyloxyC.sub.1-C.sub.10alkyl;
heterocycyl C.sub.1-C.sub.6 alkyl; hydroxyl carbonyl
C.sub.1-C.sub.100alkyl; C.sub.6-C.sub.10 aryl C.sub.1-C.sub.6 alkyl
oxy carbonyl amino C.sub.1C.sub.10alkyl; amino
C.sub.1-C.sub.10alkyl; halo
C.sub.1-C.sub.10alkylcarbonyloxyC.sub.1-C.sub.10alkyl;
hydroxyC.sub.1-C.sub.10alkyl; heterocycyl; C.sub.6-C
.sub.10arylC.sub.1-C6alkyl; each group being optionally substituted
by one or more substituents selected from C.sub.1-C.sub.6alkyl,
hydroxyl, oxo, or wherein said at least one carbon atom in the
heterocyclyl is optionally substituted by one or more oxo group, or
wherein at least one nitrogen atom in the heterocycly is optionally
substituted by an oxyl free radical and the reaction is performed
without solvent. The temperature of the reaction can be
140-190.degree. C. in bulk conditions; the catalyst preferably has
a general formula M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q. The
temperature of the reaction can be 110-190.degree. C. in bulk
conditions; the catalyst preferably has general formula (III).
[0097] In an embodiment, the compound is a polymer selected from
the group comprising polyolefin, polyester, polycarbonate,
polypropylene, polyethylene, poly (L) lactic acid, poly (D) lactic
acid, poly (D,L) lactic acid, polybutylene succinate,
polycaprolactone, polytrimethylene carbonate,
polyalkylenecarbonate, polysiloxane, polyether, polystyrene,
polyisoprene, polyamine, polyamide, polyvinyl alcohol,
polyurethane, polyacrylate and polyaminoacid, and containing n OH
and/or NH.sub.2 group, where n is an integer greater than or equal
to 1, and the reaction can be performed with or without solvent.
The temperature of the reaction can be 90-120.degree. C. when
solvent is used; preferably the catalyst has general formula
M(Y.sup.1,Y.sup.2, . . . Y.sup.p).sub.q. The temperature of the
reaction can be 90-120.degree. C. when solvent is used; preferably
the catalyst has general formula (III).
[0098] The temperature of the reaction can be at least 140.degree.
C., preferably 140-190.degree. C. when no solvent is used; the
catalyst preferably has general formula M(Y.sup.1,Y.sup.2, . . .
Y.sup.p).sub.q. The temperature of the reaction can be at least
90.degree. C., preferably 90-120.degree. C. when solvent is used;
the catalyst preferably has general formula (III).
[0099] The mole ratio of lactide to the compound.n, may be equal to
or below 70, for example, 7 to 60, for example, 7 to 40 i.e. the
lactide is in excess. Compound.n refers to the number of moles of
compound multiplied by the total number (n) of OH and/or NH.sub.2
groups in the compound. The letter n refers to the total number of
OH and/or NH.sub.2 groups present in the compound. More
specifically, n is the number OH groups when the compound contains
OH groups but not NH.sub.2 groups, or n is the number NH.sub.2
groups when the compound contains NH.sub.2 groups but not OH
groups, or n is the number OH groups and NH.sub.2 groups combined
when the compound contains mix of both OH groups and NH.sub.2
groups. The OH and NH.sub.2 groups are part of the compound by
covalent attachment.
[0100] Suitable solvents include toluene, xylene, THF,
C.sub.4-C.sub.20 alkane optionally branched (heptane hexane,
isobutane), ethyl acetate DMF or mixture thereof.
[0101] As a result, the instant invention can provide a simplified
process (e.g. one-pot-one-step), which reduces manufacturing costs.
Solvent is optional. Oligomerisation can proceed under normal
pressure. Both batch and continuous processes (plug-flow) can be
considered. Advantageously high conversion in short reaction time
can be obtained. The compound can also be used to introduce
additional functionalities into the lactic acid oligomers. The
products can be well defined. Narrow polydispersity could be
observed in terms of final molecular weight. Low amount of
by-products were observed. It is a versatile process, giving access
to broad range of products in the same production unit. The same
production unit for very high molecular weight PLA can be readily
used to make oligomers.
[0102] Defining the mole ratio leads to a lactic acid chain formed
by reaction of 70 or less lactides; hence the upper limit of the
molecular weight of the oligomer is determined by this ratio.
Typically a lactic acid oligomer prepared according to the process
will have a (number average molecular weight (Mn) minus the
molecular weight of the compound)/n of up to 10 100 g/mol,
Mn ( lactic acid oligomer ) - Mw ( compound ) n .ltoreq. 10 100 g /
mol , ##EQU00004##
[0103] wherein Mn(lactic oligomer) is measured by size exclusion
chromatography, and wherein n is number of OH and NH.sub.2 groups
present in the compound. Typically between 900 and 8 900 g/mol. It
will be appreciated that the compound of the calculation is the
substance incorporated into the lactic acid oligomer.
[0104] One factor that governs the number average molecular weight
is the ratio of lactide to compound. The use of a quenching agent
that stops oligomerisation may also be used to control the number
average molecular weight.
[0105] Number average molecular weight may be determined using any
technique, for instance, using size exclusion chromatography (SEC).
Typically, elution curves are calibrated with polystyrene
standards.
[0106] According to one technique, SEC is performed using a
VISCOTEK GPC max apparatus, using tetrahydrofuran (THF) as solvent
at 25.degree. C., using a PLgel 5 .mu.m MIXED-C 200.times.75 mm
column (Aligent), at a flow rate of 1ml/min with a sample volume of
150 .mu.l, a refractive index detector, and analysis using Waters
Empower software. Elution curves are calibrated with polystyrene
standards.
[0107] Suitable the lactide to be used in the reaction can be a
racemate, or an isomer such as L,L-lactide, D,D-lactide, and
D,L-lactide. L,L-lactide is preferably used. The lactide may be
produced by any known process. A suitable process for preparing
L,L-lactide is described, for example, in WO 2004/041889 which is
incorporated herein by reference.
[0108] According to the invention, R.sup.1 can be
C.sub.1-C.sub.20alkyl. For example R.sup.1 is
C.sub.1-C.sub.18alkyl, for example R.sup.1 is
C.sub.1-C.sub.14alkyl, for example R.sup.1 is
C.sub.1-C.sub.12alkyl, for example R.sup.1 is
C.sub.1-C.sub.10alkyl, for example, R.sup.1 is C.sup.1-C.sup.3
alkyl or C.sup.5-C.sup.20alkyl. R.sup.1 can be selected from ethyl,
propyl, prop-2-yl or octyl. When R.sup.1 is octyl, n is preferably
1. When R.sup.1 is propyl, n is preferably 1 or 3. According to the
invention, R.sup.1 can be hydroxyl C.sub.1-C.sub.3 or hydroxyl
C.sub.5-C.sub.10 alkyl, and n is 2. When R.sup.1 is ethyl, n is
preferably 2. X.sup.1 is preferably hydroxyl.
[0109] According to the invention, R.sup.1 can be
C.sub.3-8cycloalkyl, for instance, R.sup.1 can be
C.sub.3-8cycloalkyl, for instance, R.sup.1 can be
C.sub.3-6cycloalkyl, for instance, R.sup.1 can be
C.sub.3-5cycloalkyl. R.sup.1 can be selected from cyclopropyl,
cyclobutyl, cyclopentyl, or cyclohexyl.
[0110] According to the invention, R.sup.1 can be C.sub.2-C.sub.20
alkenyl, for instance, R.sup.1 can be C.sub.2-C.sub.18 alkenyl, for
instance, R.sup.1 can be C.sub.2-C.sub.16 alkenyl, for instance,
R.sup.1 can be C.sub.2-C.sub.14alkenyl, for instance, R.sup.1 can
be C.sub.2-C.sub.12 alkenyl, for instance, R.sup.1 can be
C.sub.2-C.sub.10 alkenyl, for instance, R.sup.1 can be
C.sub.2-C.sub.8 alkenyl, for instance, R.sup.1 can be
C.sub.2-C.sub.6 alkenyl, for instance, R.sup.1 can be
C.sub.2-C.sub.4alkenyl. R.sup.1 can be selected from ethenyl,
propenyl, buten-1-yl, buten-2-yl, or another longer chain
alkenyl.
[0111] According to the invention, R.sup.1 can be
C.sub.2-C.sub.10alkenylcarbonyloxyC.sub.1-C.sub.10alkyl. For
example R.sup.1 can be
C.sub.2-C.sub.6alkenylcarbonyloxyC.sub.1-C.sub.6alkyl, for example
R.sup.1 can be
C.sub.2-C.sub.4alkenylcarbonyloxyC.sub.1-C.sub.4alkyl. R.sup.1 can
be selected from prop-2-enecarbonyloxyethyl,
prop-2-enecarbonyloxypropyl, prop-2-enecarbonyloxymethyl,
ethylenecarbonyloxymethyl, ethylenecarbonyloxyethyl,
ethylenecarbonyloxypropyl. n is preferably 1. X.sup.1 is preferably
hydroxyl. In a particular embodiment, the oligomer so formed can be
used for the preparation of modified polystyrene. This is
particularly applicable when R.sup.1 is C.sub.2-C
.sub.10alkenylcarbonyloxyC.sub.1-C.sub.10alkyl, such as
prop-2-enecarbonyloxyethyl.
[0112] According to the invention, R.sup.1 can be heterocyclyl, for
example, R.sup.1 can be heterocyclyl optionally substituted by one
or more substituents selected from C.sub.1-C.sub.6alkyl, hydroxyl,
or oxo. The heterocyclyl may be a 3, 4, 5, 6, 7, 9 or 10 member
monocyclic ring system, containing 1, 2 or 3 heteroatoms each
independently selected from O or N. According to the invention
R.sup.1 can be an epoxymethyl, or dioxolone-2-oxo-methyl. n is
preferably 1. X.sup.1 is preferably hydroxyl.
[0113] According to the invention, R.sup.1 can be hydroxylcarbonyl
C.sub.1-C.sub.100alkyl, for example, R.sup.1 can be
hydroxylcarbonylC.sub.1-C.sub.50alkyl, R.sup.1 can be
hydroxylcarbonylC.sub.1-C.sub.25alkyl, R.sup.1 can be
hydroxylcarbonylC.sub.1-C.sub.15 alkyl, R.sup.1 can be
hydroxylcarbonylC.sub.1-C.sub.10alkyl, R.sup.1 can be
hydroxylcarbonylC.sub.1-C.sub.6alkyl, or R.sup.1 can be hydroxyl
carbonylC.sub.1-C.sub.4alkyl. n is preferably 1. X.sup.1 is
preferably hydroxyl.
[0114] According to the invention, R.sup.1 can be
C.sub.6-C.sub.10arylC.sub.1-C.sub.6alkyloxycarbonylaminoC.sub.1-C.sub.10a-
lkyl, for example, R.sup.1 can be
C.sub.6-C.sub.8arylC.sub.1-C.sub.4alkyloxycarbonylaminoC.sub.1-C.sub.6
alkyl, for example R.sup.1 can be
C.sub.6-C.sub.7arylC.sub.1-C.sub.4alkyloxycarbonylaminoC.sub.1-C.sub.4
alkyl, for example R.sup.1 can be phenylmethoxycarbonylaminopropyl.
n is preferably 1. X.sup.1 is preferably hydroxyl.
[0115] According to one embodiment of the invention, the oligomer
so formed, when R.sup.1 is
C.sub.6-C.sub.10arylC.sub.1-C.sub.6alkyloxycarbonylaminoC.sub.1-C.sub.10a-
lkyl, can be further treated to remove the
C.sub.6-C.sub.10arylC.sub.1-C.sub.6alkyloxycarbonyl group, thereby
leaving the amino C.sub.1-C.sub.10 alkyl part of the compound
attached to the oligomeric lactic acid. Treatment is preferably
with a suitable base such as piperidine, optionally in the presence
of a suitable solvent such as in dichloromethane.
[0116] According to the invention, R.sup.1 can be
haloC.sub.1-C.sub.10alkylcarbonyloxyC.sub.1-C.sub.10alkyl, For
example, R.sup.1 can be
haloC.sub.1-C.sub.8alkylcarbonyloxyC.sub.1-C.sub.10alkyl, for
example R.sup.1 can be
haloC.sub.1-C.sub.6alkylcarbonyloxyC.sub.1-C.sub.10alkyl, for
example R.sup.1 can be
haloC.sub.1-C.sub.6alkylcarbonyloxyC.sub.1-C.sub.10alkyl, for
example R.sup.1 can be
haloC.sub.1-C.sub.4alkylcarbonyloxyC.sub.1-C.sub.10alkyl, for
example R.sup.1 can be
haloC.sub.1-C.sub.8alkylcarbonyloxyC.sub.1-C.sub.8alkyl, for
example R.sup.1 can be haloC.sub.1-C.sub.8alkylcarbonyl
oxyC.sub.1-C.sub.6alkyl, for example R.sup.1 can be
haloC.sub.1-C.sub.8alkylcarbonyloxyC.sub.1-C.sub.4alkyl, for
example R.sup.1 can be bromideisoethylcarbonyloxyethyl. n is
preferably 1. X.sup.1 is preferably hydroxyl.
[0117] According to the invention, R.sup.1 can be a heterocycyl,
for example, R.sup.1 can be a heterocycyl monocyclic 4 to 6 member
ring system, having 1, 2,or 3 heteroatoms. The heteroatom may be O
or N. According to the invention, R.sup.1 can be 6-membered ring
where the heteroatom is N. The heterocycyl can be substituted by
one or more substituents each independently selected from
C.sub.1-C.sub.6alkyl, oxyl free radical, oxo. R.sup.1 can be
2,2,6,6 tetramethylpiperidinyl-1-oxyl, preferably having the
formula (II): wherein the asterisk indicates the point of
attachment of X.sup.1. X.sup.1 is preferably hydroxyl. n is
preferably 1, the compound is 2,2,6,6 tetramethyl
##STR00003##
[0118] In a particular embodiment, the oligomer so formed when
R.sup.1 is heterocycyl can be used to prepare modified polystyrene.
This is particularly applicable when R.sup.1 is heterocycyl is
substituted by an oxyl free radical, more particularly when is
R.sup.1 is 2,2,6,6 tetramethyl piperidine-1-oxyl.
[0119] According to the invention, R.sup.1 can be
C.sub.6-C.sub.10aryl C.sub.1-C.sub.6alkyl, for example, R.sup.1 can
be C.sub.6-C.sub.8arylC.sub.1-C.sub.4alkyl, for example, R.sup.1
can be C.sub.6-C.sub.8arylC.sub.1-C.sub.2alkyl for example, R.sup.1
can be benzyl. X.sup.1 is preferably amine (e.g. NH.sub.2). n is
preferably 1.
[0120] According to the invention, the compound can be a polymer,
for example, the compound can be a polyolefin, the compound can be
a polyester, the compound can be a polycarbonate, the compound can
be polypropylene, the compound can be polyethylene, the compound
can be poly (L) lactic acid, the compound can be poly (D) lactic
acid, the compound can be poly (D,L) lactic acid, the compound can
be polybutylene succinate, the compound can be polycaprolactone,
the compound can be polytrimethylene carbonate, the compound can be
polyalkylenecarbonate, the compound can be polysiloxane, the
compound can be polyether, the compound can be polystyrene, the
compound can be polyisoprene, the compound can be polyamine, the
compound can be polyamide, the compound can be polyvinyl alcohol,
the compound can be polyurethane, the compound can be polyacrylate
or the compound can be polyaminoacid; in each case the polymer
contains n OH and/or NH.sub.2 group(s), where n is an integer
greater than or equal to 1.
[0121] When the polymer contains n OH and/or NH.sub.2 group(s),
where n is an integer greater than or equal to 1, it means that at
least one OH and/or at least one NH.sub.2 group(s) may be present
in the native polymer, or that the native polymer is modified with
an hydroxyl (OH) or amine (e.g. NH.sub.2) group or both, for
instance, by end-capping at one or both ends. It will be
appreciated that n will be an integer n is an integer greater than
or equal to 2 when the polymer contains at least one OH and at
least one NH.sub.2 group. In an example, native polyvinyl alcohol
polymer or native polyacrylate polymer contains OH groups; these
polymers may optionally be end capped with OH or NH.sub.2.
According to a particular instance, the compound may be
polypropylene end-capped with an hydroxyl. The hydroxyl- or
amine-capped polymer may be formed from a polymer end-capped with a
vinyl group. For example, the compound may be formed from
polypropylene end-capped with a vinyl group.
[0122] When more than one compound is employed, it is meant that
the compounds are different. One or more compounds includes
mixtures of different polymers (i.e. polymer blends). One or more
compounds includes mixtures of different compounds having formula
(I). One or more compounds includes mixtures of different compounds
having formula (I), or mixtures of different polymers (i.e. polymer
blends). According to one aspect, one or more compounds refers to a
mixture of one or more compounds having formula (I) and one or more
polymers (i.e. polymer blends). There may be 2, 3, 4, 5, 6, 7, 8,
9, or 10 or more different compounds employed in the method.
[0123] When more than one compound is present in the method and
each compound has a different number n, for instance when the
method is performed using a blend of different polymers, the
reactions conditions are set such that the mole ratio of lactide to
(compound.n) is equal to or below 70 for each compound. This allows
each OH or NH.sub.2 group of each compound to be present where
lactide is in mole excess of each group by a factor of 70 or less.
Eq. 1 sets out the mole ratio lactide:(compound.n) for mu.sub.k
moles of lactide, m.sub.Cmp1 moles of compound 1, in which a
molecule of compound 1 contains n.sub.Cmp1 number of OH and/or
NH.sub.2 groups.
m LA n Cmp 1 m Cmp 1 .ltoreq. 70 [ Eq . 1 ] ##EQU00005##
[0124] Where there is a blend of different compounds (e.g. a
polymer blend), Eq.2 sets out the mole ratio lactide:(compound.n),
for m.sub.LA moles of lactide and a blend of different compounds
(Cmp1 to Cmp 5) containing m.sub.mp1 moles of compound 1, in which
a molecule of compound 1 contains n.sub.Cmp1 number of OH and/or
NH.sub.2 groups, m.sub.Cmp2 moles of compound 2, in which a
molecule of compound 2 contains n.sub.Cmp2 number of OH and/or
NH.sub.2 groups . . . m.sub.Cmp5 moles of compound 5, in which a
molecule of compound 5 contains n.sub.Cmp5 number of OH and/or
NH.sub.2 groups.
m LA [ n Cmp 1 m Cmp 1 ] + [ n Cmp 2 m Cmp 2 ] + + [ n Cmp 5 m Cmp
5 ] .ltoreq. 70 [ Eq . 2 ] ##EQU00006##
[0125] The value of n is at least one, for example, a value in the
range 1-10, 1-20, 1-30 or 1 to 500. Preferably n is 1, 2, 3, 4, 5,
6, 7, 8, or 10. When n is greater than 1 for a compound, the
formation of new architectures is possible via the oligomerisation
of the present process. When n=2, propeller (2-bladed) copolymers
are formed having a non-lactic acid core, and oligomeric lactic
acid blades. When n=3, star (3-bladed) copolymers are formed having
a non-lactic acid core, and oligomeric lactic acid blades.
Accordingly, the oligomer branches with a well defined length and
end groups originating from the compound. This is particular
suitable when the compound is a polymer selected from the group
comprising polypropylene, polyethylene, poly (L) lactic acid, poly
(D) lactic acid, poly (D,L) lactic acid, polysiloxane, polybutylene
succinate, polytrimethylene carbonate, polycaprolactone, polyester,
polyether, polyolefin, polystyrene, polyisoprene, polycarbonate,
polyalkylenecarbonate, polyamine, polyamide, polyvinyl alcohol,
polyurethane, polyacrylate and polyaminoacid, and containing n OH
and/or NH.sub.2 group(s), where n is an integer greater than or
equal to 1.
[0126] The terminal groups (hydroxyl or amine) of each lactic acid
oligomeric chain resulting from the process of the invention are
available for further reactions. In other words, telechelic
oligomers are formed by the process of the invention, in particular
when n>1 (e.g. n=2); these can act as macroinitiators for the
further preparation of multiblock copolymers, having a non-lactic
acid core. This is particularly suitable when the compound is a
polymer. The polymer preferably contains hydroxyl, or X.sup.1 is
preferably hydroxyl. Accordingly, a further embodiment of the
invention is a use of an oligomer prepared according to the present
method for the further preparation of multiblock copolymers
[0127] Other compounds that give some specific microstructure in
ROP of lactide could be considered such as branching agents and the
like.
[0128] The catalytic system used for producing the lactic oligomers
may be any suitable catalytic system. Suitable catalysts according
to the invention are organometallic catalysts. Examples of
organometallic catalysts follow. Suitable catalysts according to
the invention can be catalyst of general formula M(Y.sup.1,Y.sup.2,
. . . Y.sup.p).sub.q, in which M is a metal selected from the group
comprising the elements of columns 3 to 12 of the periodic table of
the elements, as well as the elements Al, Ga, In, Tl, Ge, Sn, Pb,
Sb, Ca, Mg and Bi; whereas Yl, Y.sup.2, . . . Y.sup.p are each
substituents selected from the group comprising C.sub.1-20alkyl,
C.sub.6-30aryl, C.sub.1-20alkoxy , C.sub.6-30aryloxy, and other
oxide, carboxylate, and halide groups as well as elements of group
15 and/or 16 of the periodic table; p and q are integers between 1
and 6. As examples of suitable catalysts, we may notably mention
the catalysts of Sn, Ti, Zr, Zn, and Bi; preferably an alkoxide or
a carbon/late and more preferably Sn(Oct).sub.2, Ti(OiPr).sub.4,
Ti(2-ethylhexanoate).sub.4, Ti(2-ethylhexyloxide).sub.4,
Zr(OiPr).sub.4, Bi(neodecanoate).sub.3 or Zn(lactate).sub.2.
[0129] Other suitable catalysts can be catalyst of general formula
(Ill):
##STR00004##
[0130] wherein
[0131] R.sup.2 and R.sup.3 are each independently
C.sub.1-10alkyl,
[0132] R.sup.4, R.sup.5 and R.sup.6 are each independently
C.sub.1-10alkyl, or
[0133] R.sup.4 and R.sup.5 are covalently bound to each other and
are each a methylene and
[0134] R.sup.6 is C.sub.1-10alkyl,
[0135] X.sup.2 is selected from C.sub.1-10alkyl, --OR.sup.7, or
--N(SiR.sup.8.sub.3).sub.2, R.sup.7 is C.sub.1-10alkyl, and R.sup.8
is C.sub.1-6alkyl.
[0136] R.sup.2 and R.sup.3 are each independently C.sub.1-10alkyl;
preferably, R.sup.2 and R.sup.3 are each independently
C.sub.1-6alkyl; preferably, R.sup.2 and R.sup.3 are each
independently C.sub.1-4alkyl; for example, R.sup.2 and R.sup.3 can
be each independently selected from the group consisting of methyl,
ethyl, n-propyl, i-propyl, 2-methyl-ethyl, n-butyl, i-butyl and
t-butyl; preferably, R.sup.2 and R.sup.3 can be each independently
selected from the group consisting of methyl, ethyl, i-propyl and
t-butyl; for example R.sup.2 and R.sup.3 can be each independently
selected from i-propyl or t-butyl; preferably, R.sup.2 and R.sup.3
are t-butyl,
[0137] R.sup.4, R.sup.5 and R.sup.6 are each independently
C.sub.1-10alkyl, preferably, R.sup.4, R.sup.5 and R.sup.6 are each
independently C.sub.1-6alkyl, preferably R.sup.4, R.sup.5 and
R.sup.6 are each independently C.sub.1-4alkyl, for example,
R.sup.4, R.sup.5 and R.sup.6 can be each independently selected
from the group consisting of methyl, ethyl, n-propyl, i-propyl,
2-methyl-ethyl, n-butyl, i-butyl and t-butyl; for example, R.sup.4,
R.sup.5 and R.sup.6 can be each independently selected from the
group consisting of methyl, ethyl, i-propyl and t-butyl; for
example, R.sup.4, R.sup.5 and R.sup.6 are each independently
selected from methyl or ethyl; preferably, R.sup.4, R.sup.5 and
R.sup.6 are each independently methyl, or R.sup.4 and R.sup.5 are
covalently bound to each other and are each a methylene and R.sup.6
is C.sub.1-10alkyl; preferably R.sup.6 is C.sub.1-6alkyl;
preferably, R.sup.6 is C.sub.1-4 aalkyl; for example R.sup.6 can be
selected from the group consisting of methyl, ethyl, n-propyl,
i-propyl, 2-methyl-ethyl, n-butyl, i-butyl and t-butyl; for example
R.sup.6 can be selected from the group consisting of methyl, ethyl,
i-propyl and t-butyl; for example R.sup.6 can be selected from
methyl or ethyl; for example R.sup.6 can be methyl;
[0138] X.sup.2 is selected from C.sub.1-10alkyl, --OR.sup.7, or
--N(SiR.sup.8.sub.3).sub.2, R.sup.7 is C.sub.1-10alkyl, and R.sup.8
is C.sub.1-6alkyl; preferably, X.sup.2 is selected from
C.sub.1-6alkyl, --OR.sup.7, or --N(SiR.sup.8.sub.3).sub.2, R.sup.7
is C.sub.1-6alkyl, and R.sup.8 is C.sub.1-6alkyl; preferably,
X.sup.2 is selected from C.sub.1-4alkyl, --OR.sup.7, or
--N(SiR.sup.8.sub.3).sub.2, R.sup.7 is C.sub.1-4alkyl, and R.sup.8
is C.sub.1-4alkyl; for example X.sup.2 can be selected from the
group consisting of methyl, ethyl, n-propyl, i-propyl,
2-methyl-ethyl, n-butyl, i-butyl and t-butyl, or --OR.sup.7, or
--N(SiR.sup.8.sub.3).sub.2, R.sup.7 can be selected from the group
consisting of methyl, ethyl, n-propyl, i-propyl, 2-methyl-ethyl,
n-butyl, i-butyl and t-butyl, and R.sup.5 can be selected from the
group consisting of methyl, ethyl, n-propyl, i-propyl,
2-methyl-ethyl, n-butyl, i-butyl and t-butyl; preferably, X.sup.2
can be selected from the group consisting of methyl, ethyl,
i-propyl and n-butyl, or --OR.sup.7, R.sup.7 can be selected from
the group consisting of methyl, ethyl, i-propyl and t-butyl;
preferably, X.sup.2 can be selected from --OR.sup.7, R.sup.7 can be
selected from the group consisting of methyl, ethyl, i-propyl and
t-butyl; preferably, X.sup.2 can be --OR.sup.7, and R.sup.7 is
ethyl.
[0139] In an embodiment, R.sup.2 and R.sup.3 are each independently
C.sub.1-6alkyl. Preferably, R.sup.2 and R.sup.3 can be each
independently selected from the group consisting of methyl, ethyl,
i-propyl and t-butyl; for example R.sup.2 and R.sup.3 can be each
independently selected from i-propyl or t-butyl; preferably,
R.sup.2 and R.sup.3 are t-butyl.
[0140] In an embodiment, R.sup.4, R.sup.5 and R.sup.6 are each
independently C.sub.1-6alkyl. For example, R.sup.4, R.sup.5 and
R.sup.6 can be each independently selected from the group
consisting of methyl, ethyl, i-propyl and t-butyl; preferably,
R.sup.4, R.sup.5 and R.sup.6 can be each independently selected
from methyl or ethyl; more preferably, R.sup.4, R.sup.5 and R.sup.6
can be methyl.
[0141] For example, the process can be performed with a catalyst of
Formula (III) wherein, R.sup.2 and R.sup.3 are each independently
C.sub.1-6alkyl; R.sup.4, R.sup.5 and R.sup.6 are each independently
C.sub.1-6alkyl; and X.sup.2 is selected from C.sub.1-6alkyl,
--OR.sup.7, or --N(SiR.sup.8.sub.3).sub.2, R.sup.7 is
C.sub.1-6alkyl, and R.sup.5 is C.sub.1-6alkyl.
[0142] For example, the process can be performed with a catalyst of
Formula (III) wherein, R.sup.2 and R.sup.3 are each independently
C.sub.1-6alkyl; R.sup.4 and R.sup.5 are covalently bound to each
other and are each a methylene and R.sup.6 is C.sub.1-6alkyl; and
X.sup.2 is selected from C.sub.1-6alkyl, --OR.sup.7, or
--N(SiR.sup.8.sub.3).sub.2, R.sup.7 is C.sub.1-6alkyl, and R.sup.8
is C.sub.1-6alkyl.
[0143] For example, the oligomerisation of lactide into lactic acid
oligomers can be performed with a catalyst of Formula (III)
wherein, R.sup.2 and R.sup.3 are each independently C.sub.1-4alkyl;
R.sup.4, R.sup.5 and R.sup.6 are each independently C.sub.1-4alkyl,
X.sup.2 is selected from C.sub.1-4alkyl, --OR.sup.7, or
--N(SiR.sup.8.sub.3).sub.2, R.sup.7 is C.sub.1-4alkyl, and R.sup.8
is C.sub.1-4alkyl.
[0144] For example, the oligomerisation of lactide into lactic acid
oligomers can be performed with a catalyst of Formula (III)
wherein, R.sup.2 and R.sup.3 are each independently C.sub.1-4alkyl;
R.sup.4 and R.sup.5 are covalently bound to each other and are each
a methylene and R.sup.6 is C.sub.1-4alkyl; and X.sup.2 is selected
from C.sub.1-4alkyl, --OR.sup.7, or --N(SiR.sup.8.sub.3).sub.2,
R.sup.7 is C.sub.1-4alkyl, and R.sup.8 is C.sub.1-4alkyl.
[0145] In a preferred embodiment, R.sup.2 and R.sup.3 are each
independently C.sub.1-4alkyl, preferably t-butyl or isopropyl;
R.sup.4, R.sup.5 and R.sup.6 are each independently C.sub.1-2alkyl,
X.sup.2 is --OR.sup.7, and R.sup.7 is C.sub.1-2alkyl.
[0146] In a preferred embodiment, R.sup.2 and R.sup.3 are each
independently C.sub.1-4alkyl, preferably t-butyl or isopropyl;
R.sup.4 and R.sup.5 are covalently bound to each other and are each
a methylene and R.sup.6 is C.sub.1-2alkyl; X.sup.2 is --OR.sup.7,
R.sup.7 is C.sub.1-2alkyl.
[0147] In an embodiment, the catalyst is Formula (IIIa), (IIIb),
(IIIc) or (IIId),
##STR00005##
[0148] wherein R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and
X.sup.2 have the same meaning as that defined above.
[0149] In an embodiment, said catalyst of Formula (III) is
(2,4-di-tert-butyl-6-(((2-(dimethylamino)ethyl)(methyl)amino)methyl)pheno-
xy)(ethoxy)zinc, also referred to as "DDTBP-Zn (OEt)" represented
by Formula (IV).
##STR00006##
[0150]
(2,4-di-tert-butyl-6-(((2-(dimethylamino)ethyl)(methyl)amino)
methyl) phenoxy)(ethoxy)zinc can be prepared as described in
Williams et al. (J. Am. Chem. Soc., 2003, 125, 11350-59) hereby
incorporated by reference.
[0151] The polymerization of lactide is performed in the presence
of catalyst. The catalyst may be used in any amount where the
lactide is in excess to catalyst. For instance, the mole ratio of
lactide to catalyst may be equal to or below 200 000, 100 000, 80
000, 60 000, 40 000, 20 000, 10 000, 5 000, 3000, between 200 and 3
000, between 200 and 2800, or between 200 and 2 500.
[0152] Typically, the process of the invention is performed in a
closed reaction vessel under an inert gas (e.g. nitrogen, helium)
atmosphere. Preferably it is performed under melt conditions, in
the absence of additional solvent. Preferably, the process is
performed by contacting the lactide with the catalyst and compound
in a reactor preferably equipped with an agitator for high
viscosity or extrusion in a extruder (or horizontal reactor) in
single, double or multiple screws in an inert atmosphere in the
presence of argon or nitrogen. However, it can also take place
under ambient. The temperature is regulated, for example, by
immersion of the vessel or reactor in an oil bath. The reaction may
be terminated.
[0153] The oligomerisation reaction may optionally be stopped using
any known termination technique. Typically, it is quenched using an
acid chloride. The acid chloride preferably has the formula
Cl--CO--R.sup.9, where R.sup.9 is selected from the group
consisting of: alkynyl, aminoalkyl, alkyl, R.sup.1. Most
preferably, R.sup.9 is pent-1-ylnyl or aminoethyl. Alternatively,
the oligomerisation reaction may be quenched by opening the
reaction vessel, whereby atmospheric oxygen deactivates the
catalyst.
[0154] The invention also relates to an oligomer prepared according
to the method of the invention. The product may have a (number
average molecular weight (Mn) minus the molecular weight of the
compound)/n equal to or less than 10 100 g/mol, typically 900 to 8
900 g/mol. It will be appreciated that the compound is the compound
incorporated into the lactic acid oligomer. When there is a mixture
of compounds (e.g. polymer blend) a blend of oligomers results. For
each compound of the polymer blend the resulting product has a (Mn
minus the molecular weight of the compound)/n equal to or less than
10 100 g/mol, typically 900 to 8 900 g/mol.
EXAMPLES
[0155] 1. Alcohol as Transfer Agent
[0156] Oligomeric L-lactic acids were synthesized by the
ring-opening polymerization of L-Lactide with an Sn(Oct).sub.2
catalyst (Cat) in the presence of various kinds of alcohol as
transfer agents that are compounds having formula (I). Three
different alcohols were used in separate experiments, namely
1-Octanol, isopropanol and HEMA (2-hydroxyethyl metacrylate). The
oligomeric products resulting from the various transfer agents are
illustrated in Scheme 1 below.
##STR00007##
[0157] The ring opening polymerization of L-Lactide was performed
in bulk. The reactions were carried out at a temperature ranging
between 150.degree. C. and 185.degree. C. Products were analysed by
SEC. SEC was performed using a VISCOTEK GPC max instrument, with
tetrahydrofuran (THF) as solvent at 25.degree. C., using a PLgel 5
.mu.m MIXED-C 200.times.75 mm column (Aligent), at a flow rate of
1ml/min with a sample volume of 150 .mu.l, a refractive index
detector, and analysis using Waters Empower software. Elution
curves were calibrated with polystyrene standards.
[0158] The results of the experiments are presented in Table 1
below.
TABLE-US-00001 TABLE 1 Polymerization of L-LA in bulk at 150 and
185.degree. C. using Sn(Oct).sub.2/ROH catalyst system. Ratio Ratio
T Time Conv M.sub.n theo W.sub.n SEC .sup.a W.sub.n SEC .sup.a
Example ROH LA/Sn LA/ROH (.degree. C.) (min) (%) (g/mol) (PS) (PLA)
M.sub.w/M.sub.n .sup.b 1 Octanol 2 186 36.4 150 30 93.5 5 035 9 971
5 783 1.26 2 Octanol 2 154 35.9 185 30 95.1 5 046 10 276 5 960 1.68
3 Octanol 784 7.8 150 30 82.2 1 058 2 530 1 465 1.21 4 Octanol 773
7.7 185 30 92.3 1 157 4 208 2 332 1.45 5 Octanol 246 4.1 150 60
67.4 398 1 610 933 1.23 6 Octanol 244 4.06 185 30 71.5 485 2 110 1
223 1.23 7 .sup.iPrOH 2 039 33.9 150 30 93.4 4 630 8 853 5 135 1.36
8 .sup.iPrOH 713 7.1 150 30 83.4 916 2 076 1 204 1.23 9 .sup.iPrOH
239 3.9 150 60 62.4 417 1 708 992 -- 10 HEMA 1 969 32.8 150 30 96.2
5 042 8 473 4 914 1.26 11 HEMA 706 7.06 150 30 84.1 985 2 236 1 296
1.19 12 HEMA 247 4.1 185 30 69 540 1 688 979 -- .sup.a Number
average molecular weight of the oligomers as determined by SEC in
THF vs. polystyrene (PS) standards and corrected by 0.58. .sup.b
Molecular weight distributions calculated from SEC traces.
[0159] The end-group structure of the polylactides was analyzed by
.sup.1H and .sup.13C NMR, which allowed us to calculate more
precisely the molecular weights of the resulting polymers.
Moreover, the GPC is a good analysis to determine the PLLA
molecular weights too. Characterization of the PLA oligomers by
.sup.1H and .sup.13C NMR analysis in CDCl.sub.3 revealed, besides
the main polymer chain typical resonances, clearly the presence of
both a hydroxymethyl and an alkoxy ester chain-end.
[0160] 2. Amine as Transfer Agent
[0161] Oligomeric L-lactic acids were synthesized by the
ring-opening polymerization of L-Lactide with an Sn(Oct).sub.2
catalyst in the presence of an amine transfer agent, benzyl amine.
The reaction scheme is illustrated in Scheme 2 below.
##STR00008##
[0162] The ring opening polymerization of L-Lactide was performed
in bulk for 30 minutes. The reactions were carried out at a
temperature ranging between 150.degree. C. and 185.degree. C.
Products were analysed by SEC. SEC was performed using a VISCOTEK
GPC max instrument, with tetrahydrofuran (THF) as solvent at
25.degree. C., using a PLgel 5 .mu.m MIXED-C 200.times.75 mm column
(Aligent), at a flow rate of 1ml/min with a sample volume of 150
.mu.I, a refractive index detector, and analysis using Waters
Empower software. Elution curves were calibrated with polystyrene
standards. The results of the experuments are presented in Table 2
below.
TABLE-US-00002 TABLE 2 Oligomerisation of L-lactide in bulk at
150.degree. C. and 185.degree. C. using Sn(Oct).sub.2 catalyst
system and BnNH.sub.2 transfer agent. T Time Conv W.sub.n .sub.theo
W.sub.n .sub.SEC .sup.a W.sub.n .sub.SEC .sup.a Example RNH.sub.2
LA/Sn LA/RNH.sub.2 (.degree. C.) (min) (%) (g/mol) (PS) (PLA)
M.sub.w/M.sub.n .sup.b 13 BnNH.sub.2 1 879 31.3 150 30 89.9 4 161 8
337 4 835 1.17 14 BnNH.sub.2 2 120 35.3 185 30 92.4 4 808 10 112 5
865 1.65 15 BnNH.sub.2 763 7.63 150 30 84.4 945 2 135 1 238 1.18 16
BnNH.sub.2 781 7.8 185 15 74.5 980 2 140 1 240 1.24 17 BnNH.sub.2
244 60 150 60 77.3 581 2 009 1 165 1.21 .sup.a Number average
molecular weight of the oligomers as determined by SEC in THF vs.
polystyrene (PS) standards and corrected by 0.58. .sup.b Molecular
weight distributions calculated from SEC traces.
[0163] 3. Diol and Triol Transfer Agents
[0164] Oligomeric L-lactic acids were synthesized by the
ring-opening polymerization of L-Lactide with an Sn(Oct).sub.2
catalyst in the presence of a diol or triol transfer agents. This
resulted in linear telechelic dihydroxy HO-PLLA-OH, or 3-arms star
trihydroxy R-(PLLA-OH).sub.3 polymers. The transfer agents used
were diol (1,3-propanediol) or a triol (glycerol). The reaction
scheme is illustrated in Scheme 3 below.
##STR00009##
[0165] The ring opening polymerization of L-Lactide was performed
in bulk for 30 minutes. The reactions were carried out at a
temperature ranging between 150.degree. C. and 185.degree. C.
Products were analysed by SEC. SEC was performed using a VISCOTEK
GPC max instrument, with tetrahydrofuran (THF) as solvent at
25.degree. C., using a PLgel 5 .mu.m MIXED-C 200.times.75 mm column
(Aligent), at a flow rate of 1ml/min with a sample volume of 150
.mu.l, a refractive index detector, and analysis using Waters
Empower software. Elution curves were calibrated with polystyrene
standards. The results of the experiments are presented in Table 3
below.
TABLE-US-00003 TABLE 3 Polymerization of L-LA in bulk at 150 and
185.degree. C. using Sn(Oct).sub.2 catalyst and a diol (PPD)
ortriol (GLY) transfer agent. T Time Conv M.sub.n theo M.sub.n
.sub.SEC .sup.a M.sub.n .sub.SEC .sup.a Example R(OH).sub.n LA/Sn
LA/R(OH).sub.n.sup.c (.degree. C.) (min) (%) (g/mol) (PS) (PLA)
Mw/M.sub.n .sup.b 18 PPD 1 945 32.4 150 30 93.3 4 431 7 625 4 422
1.18 19 PPD 751 7.5 185 30 64.1 887 2 290 1 328 1.27 20 GLY 2 013
33.6 150 30 89.8 4 430 8 890 5 156 1.24 21 GLY 697 6.96 150 30 95.8
1 054 2 540 1 473 1.17 22 GLY 712 7.12 185 30 92.4 1 039 2 765 1604
1.34 .sup.a Number average molecular weights of the oligomers as
determined by SEC in THF vs.polystyrene (PS) standards and
corrected by 0.58. .sup.b Molecular weight distributions calculated
from SEC traces. .sup.cThe ratio is not corrected to account for n
number of OH groups.
[0166] .sup.1H and .sup.13C NMR analyses of the PLA oligomers
showed, besides the main polymer chain typical resonances, the
presence of a unique polymer chain-end identified by the
characteristic signals of a hydroxyl end-group. For the HO-PLA-OH
and HO-PLA-(OH).sub.2 issued from the diol and the triol, the
central organic moiety was also unambiguously identified. These
polymers, thanks to their hydroxyl end group, can act as
macroinitiators for the preparation of multiblock copolymers.
[0167] 4. Functional Polymer as Transfer Agent
[0168] Oligomeric L-lactic acids were synthesized by the
ring-opening polymerization of L-Lactide with an Sn(Oct).sub.2
catalyst in the presence of a hydroxyl-end capped macro polymer.
Hydroxy-end-capped polypropylene (PP) was used as macro-initiators
and transfer agents to prepare, with high efficiency, a variety
diblock and triblock copolymers. The reaction scheme is illustrated
in 4 below.
##STR00010##
[0169] The ring opening polymerization of L-Lactide was performed
in toluene. The reaction was carried out at a temperature of
110.degree. C. Products were analysed by SEC. SEC was performed
using a VISCOTEK GPC max instrument, with tetrahydrofuran (THF) as
solvent at 25.degree. C., using a PLgel 5 .mu.m MIXED-C
200.times.75 mm column (Aligent), at a flow rate of 1ml/min with a
sample volume of 150 .mu.l, a refractive index detector, and
analysis using Waters Empower software. Elution curves were
calibrated with polystyrene standards. The results of the
experiments are presented in Table 4 below.
[0170] Hydroxy-end-capped polypropylene initiators (PP-OH) which
are used in the examples below (Table 4) are derived from the
propylene. Propylene is first polymerized with a metallocene
catalyst as described in U.S. Pat. No. 6,376,418B1. The polymer is
subsequently submitted to a hydroboration/oxidation reaction in
conditions described by Gray et al.; Macromolecules 1998, 31,
3417-3423). Finally the vinyl terminated polymer chains are
converted to --OH terminated ones.
TABLE-US-00004 TABLE 4 Polymerization of L-LA in solvent at
110.degree. C. using Sn(Oct).sub.2 catalyst system and
hydroxy-end-capped polypropylene (PP-OH) as transfer agent. M.sub.n
T Time Conv Mn M .sub.n SEC .sup.a Example R(OH).sub.n LA/Sn
LA/R(OH)n.sup.c R(OH).sub.n (.degree. C.) solvent (min) (%) theo
(PLA) M.sub.w/M.sub.n .sup.b 23 PP-OH 1000 12.1 960 110 toluene 300
88 2 493 2 130 -- 24 PP-OH 1000 26.3 2 200 110 toluene 300 81 5 270
4 490 -- .sup.a Number average molecular weights of the oligomers
as determined by SEC in THF vs. polystyrene (PS) standards and
corrected by 0.58. .sup.b Molecular weight distributions calculated
from SEC traces. .sup.cThe ratio is not corrected to account for n
number of OH groups.
[0171] The alcohols, multi-ols or amines group incorporation was
confirmed by .sup.1H and .sup.13C NMR and GPC. Using, the
Sn(Oct).sub.2 precursor, varying the compound to alcohol, amine or
multi-ol, revealed the versatility of this approach, allowing the
preparation of accordingly end-functionalised HO-PLLAOR
polymers.
[0172] PP-PLA Properties
[0173] Blends of PP and PLA are known to exhibit heterogeneities
due to polymer incompatibility (polymers are not miscible with each
other). Example 23 from Table 4 is blended with a metallocene based
polypropylene resin (MR 2001, Melt Index=25 g/min) and a PLA
homopolymer prepared by ROP (Melt Index=15-30 g/min) : blend
ratio=40/40/10(wt %) PP/PLA/PP-PLA. A pure PP/PLA blend (50/50) is
prepared as comparison. The blends are done at 200.degree. C. and
100 rpm in a Haake micro-compounder.
[0174] The thermal properties (DSC curves obtained with a
heating/cooling rate of 20.degree. C./min between 20.degree. C. and
220.degree. C.) of the resulting materials are shown in FIG. 1
(PP/PLA 50/50) and FIG. 2 (PP/PLA/PP-PLA 40/40/10). They show an
improved compatibility for the blend containing PP-PLA with a
different melting profile compared to the PP/PLA blend.
[0175] After staining with RuO.sub.4, the material was analyzed by
Scanning Electron Microscopy. FIGS. 3 and 4 show the PP/PLA 50/50
and PP/PLA/PP-PLA 40/40/10 blends respectively.
[0176] These results show that the addition of PP-PLA to the PP/PLA
mixture improves the compatibility of the 2 materials.
* * * * *