Development of High-Molecular-Weight Fully Renewable Biopolyesters Based on Oxabicyclic Diacid and 2,5-Furandicarboxylic Acid: Promising as Packaging and Medical Materials

Abstract

Renewable and biodegradable linear polyesters with oxabicyclic units based on the ring-opening polymerization (ROP) have attracted considerable interest as alternatives to petrochemical-based polyesters. However, incorporating bio-based aromatic building blocks into the linear polyesters with oxabicyclic units by the ROP process is limited. Herein, we report three series of oxabicyclic renewable polyesters based on oxabicyclic diacid (OBDA), monomethyl oxabicyclic diacid (MBDA), and oxabicyclic anhydride with dimethyl substituents (d-MBDA) derived from bio-based furanics and synthesized via melt polymerization (MP). The molecular weights of the polyesters obtained from OBDA were significantly higher than those of the reported polyesters based on OBDA anhydride derivatives, leading to significantly higher glass-transition temperature (Tg) values and tensile strength. Furthermore, a series of fully bio-based copolyesters (PBOBmFn) was first obtained via the MP strategy by the incremental replacement of OBDA with bio-based 2,5-furandicarboxylic acid (FDCA). The incorporation of FDCA units significantly improved the thermal stabilities and mechanical properties of the linear polyesters with oxabicyclic units and endowed them with gas barrier properties that were better than those of commercial poly(ethylene terephthalate) (PET). The Tg values of PBOBmFn ranged from 38.8 to 40.8 °C and were comparable with that of the commercial biomedical material Vicryl. Additionally, the trade-off between OBDA and FDCA units can control the fast biodegradation and environmental durability of the PBOBmFn polyester series. PBOBmFn also showed excellent biocompatibility to and was safe for both RAW264.7 and PC12 cells. The strategy of the incorporation of FDCA building blocks via MP enhanced the comprehensive properties of the linear polyesters with oxabicyclic units; moreover, the adjustment between FDCA and OBDA units can be leveraged to control the polyester roles between packaging and biomedical fields while retaining the completely renewable nature of the parent of polyesters.