From Agri-food Residues to High-performance Sustainable Polymers: The POLYMERS-5B Pathway Toward Circular Bioplastics

This work presents the development of engineering-grade bio-based polymers derived exclusively from second-generation agri-food residues within the European project POLYMERS-5B (CBE-JU, Grant Agreement No. 101157840). Tomato pomace and olive pomace were processed through a cascaded biorefinery integrating enzymatic depolymerisation, green chemistry fractionation and immobilised-lipase polycondensation. Pilot-scale validation on batches of up to 15 kg demonstrated the reproducible synthesis of polyesters with an elastic modulus of approximately 2 GPa and a glass transition temperature of at least 80 degrees Celsius, enabling conventional industrial melt processing. Cradle-to-gate life cycle assessment indicates a reduction of about 50 per cent of CO2 emissions with respect to fossil-based PET and polycarbonate grades. Using the AI-driven C-Tech Navigator platform developed by NSBproject, the materials were benchmarked against poly(ethylene furanoate) and polyhydroxyalkanoates, identifying a market gap in automotive interiors, technical textiles and functional coatings, where waste-derived and thermally stable polymers can outperform the existing bio-based alternatives. The results confirm the industrial relevance and the scalability of the POLYMERS-5B platform, validated at Technology Readiness Level 5, and position it as a competitive circular polymer pathway for the European bioeconomy.