PROCESS FOR PREPARING BIODEGRADABLE POLYESTER COPOLYMER WITH IMPROVED CUTTING PROPERTY AND MECHANICAL STRENGTH BY EMPLOYING POLYLACTIC ACID

摘要

PURPOSE: A process for preparing a biodegradable polyester copolymer with improved cutting property is provided to enhance the productivity and to prevent the decrease of physical properties caused by the delayed cutting. CONSTITUTION: The process for preparing a biodegradable polyester copolymer, namely a 3-components copolymer of polylactic acid(PLA)/aromatic/aliphatic polyester comprises copolymerizing 20-80 parts by weight of an aromatic-aliphatic polyester oligomer with 80-20 parts by weight of polylactic acid resin by melt-mixing. In the process, the aromatic-aliphatic polyester oligomer has a polymerization degree of 10 or less, in which the aromatic component is contained in the range of 10-40 mol% and is at least one selected from a dicarboxylic acid of ROOC-Ar-COOR', or a derivative thereof, and the aliphatic component is at least one selected from a dicarboxylic acid of ROOC(CH2)nCOOR' or a derivative thereof. The polylactic acid comprises L-, D- or L,D-lactic acid having a molecular weight of 10,000 or more.