Advancements in the Sustainable Recycling of Polymer Composites

Polymer composites are widely used across industries for their superior mechanical, thermal, and functional properties, yet their complex structures pose significant challenges for sustainable recycling and end-of-life management. This chapter explores recent advancements in the sustainable recycling of polymer composites, with emphasis on chemical, mechanical, and emerging green methodologies that improve recyclability without compromising performance. A literature-based comparative analysis of recycling pathways, supported by case studies on thermoplastic and thermoset systems and techno-environmental assessments, forms the methodological foundation. Key findings from recent studies (2020–2025) highlight the effectiveness of hybrid strategies such as catalyst-assisted solvolysis and enzymatic hydrolysis in enhancing monomer recovery and fibre retention. Compatibilization techniques—including PEG incorporation, maleic anhydride grafting, and nanofiller reinforcement—further improve recyclate quality. The discussion addresses trade-offs between energy efficiency, product integrity, and process scalability, and evaluates the potential of green solvents and bio-based reinforcements in achieving circularity. While progress is notable, challenges in regulatory acceptance, economic feasibility, and industrial implementation remain. The chapter concludes with a forward-looking perspective on integrating innovative recycling technologies with sustainable materials design to close the loop on composite waste.