Synthesis and properties of novel thermoresponsive polyesters with oligo(ethylene glycol) pendent chains

A new class of thermoresponsive polyesters is prepared by alternating ring-opening copolymerization of succinic anhydride (SA) and epoxide bearing oligo(ethylene glycol) (oligo-EG) pendant chains with the number of repeat ethylene glycol unit ranging from 1 to 3. The copolymerization kinetics and their various properties are investigated in detail. The increase of oligo-EG length leads to a significant shift of the thermoresponsive transition to higher temperature. The copolymers hydrolyzed with unusual chain end cleavage mode and base acceleration feature. And the copolymers and their degradation products had no acute toxicities. The reported thermoresponsive polyesters are highly useful materials for in vivo biomedical applications.