Patent ID: 9637590
Date: 2017-05-02
CPC Classifications: C08G

Claim:
1. A method for synthesizing polylactide (PLA), the method employing RCOOCG wherein R is a nontoxic carboxylate (RCOOH) of cyclic guanidine (CG), as a catalyst and organic alcohol R′OH wherein R′ represents —CH 2 CH 3 or —(CH 2 ) 11 CH 3 as an initiator to catalyze/initiate a living ring-opening polymerization of lactide (LA), and the method comprising: a) adding monomer LA, the catalyst RCOOCG, and the initiator R′OH to a reaction still, wherein an initial molar ratio of the monomer to the catalyst is [LA] wherein [LA] b) removing air in the reaction still through a series of repeated operation of “vacuum pumping-nitrogen injection”, sealing the reaction still after a pressure in the reaction still is constant at between 1.0 and 0.1 torr; heating the reaction still with stirring to a temperature between 95 and 96° C. in 30 to 40 minutes; allowing reactants in the reaction still to react for 5 to 300 minutes at a temperature between 96±1 and 130±1° C.