Progress in Sustainable Composite Materials: From Bio-Based to Graphene-Reinforced Systems: A Review

Abstract

Traditional industries, such as fiber-aerospace, automotive, and defense, are facing challenges related to recyclability, cost-efficiency, and performance under extreme conditions, thereby accelerating the shift toward sustainable composite materials. This study investigates advancements in bio-based, graphene-reinforced, and hybrid composites by focusing on how material selection, processing methods, and analytical approaches impact the structure–property relationships critical to these applications. The research integrates reinforcement sourcing from natural fibres, graphene derivatives, and hybrid fillers with fabrication techniques and experimental design that incorporate reliability analysis and simulation to evaluate damage mechanisms. The results highlight significant trade-offs: chopped carbon fibres with a length of 17 mm enhance tensile and flexural strength by 470% and 350%, respectively; specimen size effects increase splitting tensile strength by 30%, but may reduce the modulus; elevated temperatures impact compressive strength, which can be mitigated by the inclusion of steel fibres; particulate additives decrease ductility, while PTFE enhances toughness. Progress in thermal and electrical performance includes composites exhibiting high resistivity with self-extinguishing behaviour up to 220°C, halogen-free formulations meeting UL-94 V-0 fire safety standards, graphene nanoplatelet–glass fibre composites achieving a 39% improvement, and optimised laminates reaching flexural strengths of 380 MPa. These findings underscore the necessity of balancing mechanical, thermal, and electrical properties to develop sustainable composites for demanding industrial environments.