Ring opening polymerization of propylene oxide by chitosan-supported rare earth catalytic system and its kinetics

摘要

Ring opening polymerization of propylene oxide in the presence of a new type of catalytic system composed of chitosan-supported rare earth complex, triisobutyl aluminium, and acetylacetone and its kinetics have been studied for the first time. It has been found that the characteristics of this catalytic system are of high catalytic activity, of higher stereoselectivity, and of a high molecular weight polymer of 2 x 10(6). Kinetic studies show that the polymerization rate is first order with respect to monomer concentration and catalyst concentration, respectively. The apparent activation energy of the polymerization reaction is 37.1 kJ/mol. (C) 1997 John Wiley & Sons, Inc.