主权项 |
1. A method of preparing a biodegradable polyester resin, the method comprising:
(a) synthesizing the biodegradable polyester resin having a reheating crystallization initiation temperature (Tch1), a reheating crystallization peak temperature (Tch), and a reheating crystallization end temperature (Tch2); and (b) crystallizing the biodegradable polyester resin synthesized in step (a) by cooling the biodegradable polyester resin from a temperature of T1 to a temperature of T2 and then maintaining the biodegradable polyester resin at a temperature of T2 for a time of tc, wherein Tch1, Tch, and Tch2 respectively denote an initial temperature, a peak temperature, and a final temperature of the crystallization peak that appears in a second step after a first step, wherein, in the first step, the molten biodegradable polyester resin synthesized in step (a) is cooled at a cooling rate of about 10° C./min from about 200° C. to about −50° C., and in the second step, the cooled biodegradable polyester resin is heated at a heating rate of about 10° C./min from about −50° C. to about 200° C., in a differential scanning calorimeter (DSC), T1 is a temperature between about 220° C. and about 280° C., and T2 satisfies the condition of Tch1≦T2≦Tch2. |