Synthesis and Properties of Biodegradable Poly(ester-co-carbonate) Multiblock Copolymers Comprising of Poly(butylene Succinate) and Poly(butylene Carbonate) by Chain Extension

Abstract

A series of biodegradable poly(ester-co-carbonate) multiblock copolymers consisting of poly(butylene succinate) and poly(butylene carbonate) (PBS-b-PBC) were synthesized successfully by chain-extension reaction of dihydroxyl terminated PBS-diol prepolymer and dihydroxyl terminated PBC-diol prepolymer using hexamethylene diisocyanate (HDI) as a chain extender. The chemical structures and molecular weights of copolymers were characterized by proton nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). The thermal properties, crystallization behavior, morphology and mechanical properties of PBS-b-PBC were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), phase-contrast optical microscopy (PCOM), and mechanical testing. It was found that the PBC soft segment is effective in enhancing the impact strength, while hardly decreases the melting point (Tm) of the copolymers. The resulting novel copolymers are expected to find a potential application in the area of biodegradable polymer materials.