One‐Pot Terpolymerization of CO 2 , Propylene Oxide and Lactide Using Rare‐earth Ternary Catalyst

A convenient one‐pot terpolymerization of CO 2 , propylene oxide (PO), and L ‐lactide ( L ‐LA) in short polymerization time (10 h or shorter) to afford poly(propylene carbonate‐lactide) with excellent mechanical property and thermal stability using Y(CCl 3 COO) 3 ‐ZnEt 2 ‐glycerin rare‐earth ternary catalyst is reported. The yield of the copolymerization was between 69.7 and 111.7 g/(g Zn), corresponding to L ‐LA/PO molar feed ratio varying from 0 to 0.1, and the number average molecular weight was between 5.5×10 4 and 11.9×10 4 . The L ‐LA content in the terpolymer increased from 1.1% to 34.7% when L ‐LA/PO molar feed ratio changed from 0.01 to 0.1. Introducing L ‐LA as the third comonomer could significantly improve the mechanical strength and thermal stability of PPC. For the terpolymer obtained from L ‐LA/PO molar feed ratio of 1:50, the elongation at break reached 40.5%, which is 3 times of that of pure PPC, and the thermal decomposition temperature increased by 32°C compared with pure PPC.