POLYLACTIC ACID-POLYSILOXANE COPOLYMER WITH IMPROVED IMPACT STRENGTH BY USING ISOCYANATE END SILOXANE FOR THE RING-OPENING POLYMERIZATION OF LACTIDE, AND A PRODUCING METHOD THEREOF

摘要

PURPOSE: A producing method of a polylactic acid-polysiloxane copolymer is provided to obtain the polylactic acid-polysiloxane copolymer with high molecular weight with excellent impact strength due to enhanced flexibility.;CONSTITUTION: A producing method of a polylactic acid-polysiloxane copolymer denoted by chemical formula I comprises the following steps: dehydration-reacting lactic acid to obtain lactic acid oligomer; heat-decomposing the lactic acid oligomer to obtain lactide; and adding 1-20 parts by weight of isocyanate end siloxane denoted by chemical formula II to 100 parts by weight of lactide. The dehydration reaction is conducted in the inert gas atmosphere at 100-200°C. The lactic acid oligomer has the molecular weight of 500-3,000.;COPYRIGHT KIPO 2013