Synthesis and characterization of amphiphilic triblock copolymers PAA-PHB-PAA

A new biodegradable PtBA-PHB-PtBA triblock copolymer was successfully synthesized by ATRP method with Br-PHB-Br as macroinitiator, tert-butyl acrylate as monomer and CuBr/PMDETA as the catalyst system. Cleavage of the tert-butyl ether groups of the PtBA-PHB-PtBA triblock copolymer was then performed via hydrolysis with trifluoroacetic acid as the catalyst in dichloromethane to afford the amphiphilic PAA-PHB-PAA triblock copolymer. The hydrolysis is successful but trace tert-butyl ether groups still remain in the backbone. The molecular weight characteristics and chain structures were conformed by GPC and NMR, respectively. Because of hydrophilic and biocompatibility, the amphiphilic triblock copolymers have potential applications in the field of drug release.