PREPARATION OF COPOLYMER CONTAINING POLYESTERS SEGMENT VIA RING-OPENING POLYMERIZATION OF CYCLIC ESTER MONOMER IN THE PRESENCE OF ACTIVATED AGENT

摘要

A method for preparing a block copolymer is provided to prevent a catalyst component inside a copolymer chain from being left behind after reaction termination, to easily control molecular weight and to polymerize a cyclic ester monomer at a room temperature. A method for preparing a polyalkylene glycol/plyester block copolymer uses a strong acid catalyst with pKa which is not greater than 1 as a polymerization catalyst and polyalkylene glycol containing a hydroxyl group at a chain terminal part as an initiator. The method comprises a step of polymerizing at least one or two kinds of cyclic monomer at -70 ~25 °C for 12~24 hours to prepare the polyalkylene glycol/plyester block copolymer with the whole molecule amount of 1,000~100,000 g/mole. The at least one or two kinds of cyclic monomer are selected from ester series lactide segment, caprolactone segment and glycolide segment.