Aliphatic polycarbonates, methods of making, and articles formed therefrom
View Patent ↗A method of making a polycarbonate is described. The method comprises melt reacting an ester-substituted diaryl carbonate and a multifunctional compound of the formula: in the presence of catalyst to form an oligomer comprising less than 2,000 ppm of an ester-linked terminal group, and melt polymerizing the oligomer to form a polycarbonate. Use of specific reaction conditions produces a polycarbonate having an Mw of greater than or equal to 25,000 g/mol as determined by gel-permeation chromatography relative to polystyrene standards. Polycarbonates comprising units derived from the multifunctional compound, including homopolycarbonates, aliphatic copolycarbonates further comprising units derived from an aromatic dihydroxy compound, and aliphatic polycarbonate-polyesters, are also disclosed, as are a thermoplastic composition and an article including the disclosed polycarbonates.
1. A method for the manufacture of an aliphatic polycarbonate, comprising:
melt reacting an ester-substituted diaryl carbonate of the formula:
wherein
each R 4 is independently a C 1-20 aliphatic group, C 4-20 cycloaliphatic group,or C 4-20 aromatic group,
each R 5 is independently a halogen atom, cyano group, nitro group, C 1-20 aliphatic group, C 4-20 cycloaliphatic group, or C 6-18 aromatic group, and
each f is independently 0 to 4,
with a multifunctional compound of the formula:
wherein
R 10 is a chemical bond, a C 1-40 hydrocarbon that can be unsubstituted or substituted with a hydroxy, carboxy, C 1 -C 22 alkoxycarbonyl, halogen, C 2-20 olefin,C 1-20 alkylether, or C 4 -C 30 polyoxyalkylene in which the alkylene groups each independently comprise 2 to 6 carbon atoms,
R 11 and R 12 are each independently a hydrogen or a C 1 -C 40 hydrocarbon that can be unsubstituted or substituted with a hydroxyl, carboxy, C 1 -C 22 alkoxycarbonyl, halogen, C 1-20 olefin, C 1-20 alkylether, or C 4 -C 30 polyoxyalkylene functionality in which the alkylene groups contain 2 to 6 carbon atoms, and optionally wherein at least two of R 10 , R 11 , and R 12 together form a C 2 -C 40 monocyclic, bicyclic, or tricyclic ring system optionally substituted with a heteroatom in a ring, and
R 9 is a hydroxy or C 1 -C 22 alkoxycarbonyl group;
to form a first oligomer having a weight average molecular weight of 4,000 to 12,000 g/mol, measured using gel permeation chromatography using polystyrene standards, and comprising less than 2,000 ppm of an ester-linked terminal group of the formula:
wherein each R 5 is independently a halogen atom, cyano group, nitro group, C 1-20 aliphatic group, C 4-20 cycloaliphatic group, or C 6-18 aromatic group, and f is 0 to 4, as determined by 1 H NMR; and
melt polymerizing the first oligomer in the presence of a transesterification catalyst to form the aliphatic polycarbonate.
2. The method of claim 1 , wherein the ester-substituted diaryl carbonate is of the formula:
wherein each R 4 is independently a C 1-20 aliphatic group, C 4-20 cycloaliphatic group, or C 4-20 aromatic group, and the ester-linked terminal group is of the formula:
3. The method of claim 1 , wherein R 10 is a chemical bond; and R 11 and R 12 are each independently a hydrogen or a C 1 -C 40 hydrocarbon that can be unsubstituted or substituted with an olefin or an ether, optionally wherein R 11 and R 12 together form a monocyclic, bicyclic, or tricyclic ring system optionally substituted with a heteroatom in a ring.
4. The method of claim 3 , wherein R 9 is hydroxy.
5. The method of claim 4 , wherein the multifunctional compound is an isosorbide of the formula:
6. The method of claim 4 , wherein the multifunctional compound is a C36 diol of the formula
wherein t and t′ are each independently 0 to 30, u and u′ are each independently 0 to 30, and the sum t+t′+u+u′ is 30.
7. The method of claim 1 , wherein the ester-linked terminal group is linked to a terminal group derived from a monomer used to form the polycarbonate backbone.
8. The method of claim 7 , wherein the ester-linked terminal group is linked to a terminal isosorbide group, which together have the formula
9. The method of claim 1 , wherein the multifunctional compound comprises less than or equal to 2,000 ppb by weight of an alkali metal.
10. The method of claim 1 , wherein the molar ratio of the ester-substituted diaryl carbonate to the total moles of the multifunctional compound and an optional aromatic dihydroxy compound is greater than 1.
11. The method of claim 1 , wherein the transesterification catalyst is present in an amount of less than or equal to 250 micromoles per equivalent of the ester-substituted diaryl carbonate.
12. The method of claim 1 , further comprising adding a first portion of a catalyst during melt reacting to form an oligomer and a second portion of a catalyst during melt polymerizing.
13. The method of claim 1 , wherein the transesterification catalyst comprises Na 2 HPO 4 , NaH 2 PO 4 , NaH 2 PO 3 , Na 2 HPO 3 , NaHSO 4 , Na 2 SO 4 , or a combination comprising at least one of the foregoing transesterification catalysts.
14. The method of claim 1 , further comprising removing an ester-substituted phenol byproduct during the melt reacting.
15. The method of claim 1 , further comprising removing an ester-substituted phenol byproduct during the melt polymerizing.
16. The method of claim 1 , further comprising adding an acid (a) to the ester-substituted diaryl carbonate, (b) to the first multifunctional compound, (c) during the melt reacting to form an oligomer, (d) during the melt polymerizing, or (e) a combination comprising at least one of the foregoing.
17. The method of claim 16 , wherein the acid is sulfuric acid, present in an amount greater than or equal to 1 mole per mole of alkali metal.
18. The method of claim 1 , wherein the melt reacting is at a temperature and for a time effective to form the oligomer and minimize formation of the ester-linked terminal group in the oligomer.
19. The method of claim 18 , wherein the melt reacting is at a maximum temperature of 220° C. to 320° C., for a maximum time of 0.5 minutes to 30 minutes.
20. The method of claim 18 , wherein the ester-linked terminal group is present an amount of less than or equal to 2,000 ppm by weight of the polycarbonate, as determined by 1 H NMR.
21. The method of claim 1 , wherein the polycarbonate comprises greater than or equal to 50 mole percent of carbonate units derived from the reaction of the ester-substituted diaryl carbonate and the multifunctional compound.
22. The method of claim 1 , wherein the polycarbonate has a weight average molecular weight of greater than or equal to 25,000 grams per mole as determined by gel permeation chromatography relative to polystyrene standards.
23. The method of claim 1 , further comprising melt reacting the ester-substituted diaryl carbonate with an additional multifunctional compound different from the multifunctional compound, an aromatic dihydroxy compound, a dicarboxylic acid, or a combination comprising at least one of the foregoing.
24. The method of claim 1 , wherein the multifunctional compound is a combination of isosorbide and a C36 diol, the aromatic dihydroxy compound is bisphenol A, and the dicarboxylic acid is a C36 dicarboxylic acid.
25. The method of claim 1 , wherein the multifunctional compound is isosorbide, and the method further comprises melt reacting the ester-substituted diaryl carbonate with bisphenol A and a C36 dicarboxylic acid.
26. An aliphatic polycarbonate manufactured by the method of claim 1 .
27. An article comprising the aliphatic polycarbonate manufactured by the method of claim 1 .
28. A method for the manufacture of an aliphatic polycarbonate, comprising:
melt reacting an ester-substituted diaryl carbonate of the formula:
wherein each R 4 is independently a C 1-20 aliphatic group, C 4-20 cycloaliphatic group, or C 4-20 aromatic group, with an isosorbide of the formula:
to form a first oligomer having a weight average molecular weight of 4,000 to 12,000 g/mol, measured using gel permeation chromatography using polystyrene standards, and comprising less than 2,000 ppm of an ester-linked terminal group of the formula:
as determined by 1 H NMR; and
melt polymerizing the first oligomer in the presence of a transesterification catalyst to form the aliphatic polycarbonate.
29. An aliphatic polycarbonate, comprising units of the formula
wherein
R 10 is a chemical bond, a C 1-40 hydrocarbon that can be unsubstituted or substituted with a hydroxy, carboxy, C 1 -C 22 alkoxycarbonyl, halogen, C 2-20 olefin, C 1-20 alkylether, or C 4-30 polyoxyalkylene in which the alkylene groups each independently comprise 2 to 6 carbon atoms,
R 11 and R 12 are each independently a hydrogen or a C 1-40 hydrocarbon that can be unsubstituted or substituted with a hydroxyl, carboxy, C 1-22 alkoxycarbonyl, halogen, C 2-20 olefin, C 1-20 alkylether, or C 4-30 polyoxyalkylene functionality in which the alkylene groups contain 2 to 6 carbon atoms, and optionally wherein at least two of R 10 , R 11 , and R 12 together form a C 2-40 monocyclic, bicyclic, or tricyclic ring system optionally substituted with a heteroatom in a ring; and
an ester-linked terminal group of the formula:
wherein each R 5 is independently a halogen atom, cyano group, nitro group, C 1-20 aliphatic group, C 4-20 cycloaliphatic group, or C 6-18 aromatic group, and f is 0 to 4, in an amount of up to 2000 ppm as determined by 1 H NMR, and based on the parts by weight of the aliphatic polycarbonate.
30. The polycarbonate of claim 29 , comprising carbonate units of the formula
and less than 2,000 ppm, as determined by 1 H NMR, of an ester-linked terminal group of the formula:
wherein f is zero and the hydroxyl group is ortho to the carbonyl.