Synthesis and characterization of biodegradable multiblock poly(carbonate-co-esters) containing biobased monomer

Multiblock poly(carbonate-co-esters) (PBC-PBSe) containing poly(butylene carbonates) (PBC) and poly(butylene sebacate) (PBSe) were synthesized successfully via chain-extension of dihydroxyl terminated PBC (PBC-OH) and PBSe (PBSe-OH) using 1,6-hexmethylene diisocyanate (HDI) as chain extender. The chemical structures, molecular weights, crystallization behaviors, thermal, degradation as well as mechanical properties of the copolyesters were characterized by Proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FT-IR), Gel permeation chromatography (GPC), Differential scanning calorimetry (DSC), Thermogravimetry analysis (TGA), hydrolytic degradation and mechanical testing, respectively. The results indicated that the introduction of PBSe segment not only significantly enhanced the crystallization rate of PBC, but also displayed the same crystallization mechanism within the investigated crystallization temperature range despite of the variation of the PBSe segment content. Furthermore, the thermal stability and hydrolytic degradation rate of PBC-PBSe multiblock copolymers increases with increasing PBSe content. The mechanical properties of copolymers can be adjusted by changing the feed composition.