Synthesis, characterization and properties of a bio-based poly(glycerol azelate) polyester

Abstract

The bio-based poly(glycerol azelate) (PGAz) polyester was synthesized by catalyst-free polycondensation. Increasing the azelaic acid: glycerol molar ratio in the preparation of the prepolymer from 1.0:1.0 to 1.6:1.0 or increasing the curing time of the PGAz sheets from 24 to 48 h both resulted in an increased level of branching and crosslinked networks of the molecular chains. These in turn improved the mechanical properties of the PGAz sheets, in terms of the Young's modulus and tensile strength. Analysis of the dynamic mechanical properties confirmed that PGAz had a rubbery state at room temperature and a glass transition temperature in the range of −28.43 to −23.40 °C, depending on the crosslinking density of PGAz. The PGAz sheets underwent hydrolytic degradation in phosphate buffered saline over 2 weeks and in moist soil burial over 6 months. The properties of the PGAz sheets are potentially suitable for applications in human surgery, such as for tissue engineering scaffolds, with a faster biodegradation rate than currently used biomaterials like poly(glycerol sebacate).