Polylactide thermosets using a bis(cyclic diester) crosslinker

Abstract

Features such as the renewability and biodegradability of polylactide (PLA) have resulted in numerous applications in biomedical and commodity polymers. However, the brittle nature of PLA hinders its wider implementation; consequently, investigations have focused on improving its mechanical properties. This work describes the preparation of PLA thermosets that are crosslinked with a novel bis(cyclic diester) containing an aliphatic chain, as a strategy to modify the mechanical properties. Kinetic studies with monofunctional model monomers showed reactivities comparable to lactide (LA) in the presence of 1,1,3,3-tetramethylguanidine as the catalyst, which additionally provided good control over the ring-opening polymerisation. Despite the low Young’s modulus and tensile strength, the crosslinked materials prepared with the bis(cyclic diester) demonstrated high ductility when compared to high molecular weight PLLA, a property that was attributed to the presence of a flexible chain in the crosslinker.