Recent advances in thermomechanical properties of PLA-based biopolymer composites for biomedical applications

Biopolymer composites have become promising materials in recent years owing to their biomedical properties, including tunable mechanical properties, biocompatibility, and biodegradability. The thermomechanical characteristics of biopolymer composites are crucial for determining factors such as safety, dimensional stability, and responsiveness to applied forces. They also help select appropriate materials that are both thermally and mechanically viable. The goal of this review article is to provide an overview of recent developments in polylactic acid (PLA)-based biopolymer composites, with a focus on thermomechanical properties that are critical for biomedical applications. In addition to its similarity to human bone, hydroxyapatite (HA) has been used as a primary reinforcement in various biomedical applications due to its excellent bioactivity, biodegradability, and osteoconductivity. Recent advances in nanotechnology have enabled nanoparticles to significantly expand research on biopolymers, as they can be readily incorporated into existing biopolymer systems. Graphene oxide (GO) and reduced graphene oxide (rGO) are the most widely used secondary reinforcements. To date, the PLA/FGNP composite has exhibited a 261 % enhancement in elastic modulus, and the PLA/CS/GO composite has exhibited a 232 % enhancement in tensile strength in bone tissue engineering applications. For thermal properties, the PLA/HA composite showed an increase in residue percentage from 3.8 % to 19.4 % at 350 °C, indicating potential for bone regeneration applications. Since most recent literature has used additive manufacturing to fabricate composites, this technique and hybrid nanoparticles are expected to dominate future biopolymer research.