Copolymerization of Propylene Oxide and CO<SUB>2</SUB> Catalyzed by a Rare Earth Borohydride-Diethylzinc-Glycerine Ternary System

Abstract

A ternary catalytic system composed of rare earth borohydrides, diethylzinc, and glycerine has been developed and found to be effective for the copolymerization of propylene oxide (PO) with carbon dioxide. The effect of catalyst composition and reaction conditions on the copolymerization was examined through orthogonal experiments. With Y(BH4)(3)center dot 3THF-ZnEt2-glycerine molar ratio of 3:60:20, the highest turnover frequency (TOF) of 4 908 g/(mol.h) was achieved at 80 degrees C and 3.0 MPa of CO2 using 1,2-dimethoxyethane as solvent. The poly(propylene carbonate) had a carbonate unit content of 95.7% and number-average molecular mass of 6.97 x 10(4).