METHOD FOR PREPARING BIODEGRADABLE POLYESTER COPOLYMER AND POLYESTER COPOLYMER PREPARED THEREBY
The present invention provides a method of preparing a polyester-based polymer and a polyester-based polymer prepared by the method. The method of preparing the polyester-based polymer includes a prepolymerization step of polymerizing a dicarboxylic acid compound (A), a diol compound (B), and a carbodiimide compound (C) at 160-220° C. to produce a prepolymer; and a condensation polymerization step of performing a condensation polymerization of the prepolymer at 200-250° C., under a vacuum pressure of 0.1 to 2 Torr.
1 . A method of preparing a biodegradable polyester-based polymer including:
a prepolymerization step of polymerizing a dicarboxylic acid compound (A), a diol compound (B), and a carbodiimide compound (C), which is represented by Formula 1 below, at 160-220° C. to produce a prepolymer; and
a condensation polymerization step of performing a condensation polymerization of the prepolymer at 200-250° C., under a vacuum pressure of 0.1 to 2 Torr:
wherein X is selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1 -C 20 alkyl group, a substituted or unsubstituted C 1 -C 20 alkoxy group, a substituted or unsubstituted C 2 -C 20 alkenyl group, a substituted or unsubstituted C 2 -C 20 alkynyl group, a substituted or unsubstituted C 1 -C 20 heteroalkyl group, a substituted or unsubstituted C 6 -C 30 aryl group, a substituted or unsubstituted C 7 -C 30 arylalkyl group, a substituted or unsubstituted C 5 -C 30 heteroaryl group, and a substituted or unsubstituted C 3 -C 30 heteroarylakyl group.
2 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein the amount of the carbodiimide compound (C) used may be less than 0.1-1 wt % with respect to the total weight of the composition consisting of the dicarboxylic acid compound (A), the diol compound (B), and the carbodiimide compound (C).
3 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein the ratio of the amount of the dicarboxylic acid compound (A) used to the amount of the diol compound (B) used is 1:1 to 1:4, based on the molar ratio.
4 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein, when two species of the dicarboxylic acid compound are used, the ratio between the amounts of the above two species is 1:1 to 1:1.3, based on the molar ratio.
5 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein X is a substituted or unsubstituted C 6 -C 15 aryl group.
6 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein the dicarboxylic acid compound (A) is one or more species selected from the group consisting of a substituted or unsubstituted C 4 -C 10 aliphatic dicarboxylic acid, a substituted or unsubstituted C 8 -C 20 aromatic dicarboxylic acid, a substituted or unsubstituted C 4 -C 10 aliphatic diester, and a substituted or unsubstituted C 8 -C 20 aromatic diester.
7 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein the diol compound (B) is one or more species selected from the group consisting of a substituted or unsubstituted C 2 -C 10 aliphatic diol, and a substituted or unsubstituted C 6 -C 20 aromatic diol.
8 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein the prepolymerization step is carried out in the presence of at least one of a catalyst and a thermostabilizer.
9 . The method of preparing a biodegradable polyester-based polymer according to claim 1 , wherein the prepolymerization step includes
a first prepolymerization step of polymerizing a dicarboxylic acid compound (A) and a part of the diol compound (B) to produce a first prepolymer, and
a second prepolymerization step of polymerizing the first prepolymer and the remainder of the diol compound (B) to produce a second prepolymer, and
wherein the carbodiimide compound (C) is used in at least one of the first prepolymerization step, the second prepolymerization step, and the condensation polymerization step.
10 . The method of preparing a biodegradable polyester-based polymer according to claim 9 , wherein the amount of the diol compound (B) used in the second prepolymerization step may be 1.0-1.3, based on 1 mol of the amount of the diol compound (B) used in the first prepolymerization step.
11 . A biodegradable polyester-based polymer prepared by the method of claim 1 .
12 . The biodegradable polyester-based polymer according to claim 11 , having a hydrolysis rate of 0-20%.
13 . The biodegradable polyester-based polymer according to claim 11 , having an acid value of 4 mg KOH/g or lower.