A physical-mechanical study of bio-composites based on lignocellulosic agri-food waste and PBAT/PLA

The increasing environmental problems caused by traditional plastics and the urgent need for ecofriendly materials have led to an increasing search for biodegradable polymers with improved performances. This study investigates the development and characterization of biodegradable biocomposites composed of a blend of PBAT/PLA as matrix, added with 30% of lignocellulosic agro-food fillers, including Beer Spent grain (BSG), olive pomace (OP), coffee silver skin (CSS) and mandarin pomace (MP). The aim is to valorize organic residues while improving the functional performance of biopolymers for sustainable applications.The biocomposites were characterized by rheological (melt flow rate, mixing torque), thermal (TGA, DSC) and mechanical (tensile tests) properties, and surface characteristics (contact angle, roughness). In general, the biocomposites showed higher stiffness, tensile strength and lower deformability compared to PBAT/PLA. However, the mechanical values remain appreciable for "Reuse-Design- Applications".These results highlight the potential of agro-food waste as an effective filler for bioplastics. The study supports the principles of circular economy by transforming food industry byproducts into value-added materials, offering a viable strategy to reduce fossil-based plastic pollution and promote sustainable material innovation [1].