Obtaining biodegradable plastics from by-products of orange and poly(lactic acid) processing

Abstract

The current pace of production and consumption of plastic products brings environmental problems at various points in the production line, from the unrestrained extraction of non-renewable resources, such as oil, to the improper disposal of products and, in many cases, non-recyclability. In this scenario, the concept of circular economies emerges to replace linear production chains, within which the development of biodegradable and renewable materials is included, as well as the reuse of industrial waste. The production of orange juice is a sector in which Brazil is a world leader; however, high amounts of solid waste are generated in this industry. Such by-products are predominantly made up of cellulose, pectin, lignin, hemicellulose and extractives, which in this Project will be analyzed for the production of sustainable materials based on the compostable polymer poly(lactic acid) (PLA). Despite the feasibility of converting these residues into continuous filaments, demonstrated in previous studies, their hydrophilicity and mechanical properties still preclude their use in packaging. Therefore, its association with more hydrophobic and mechanically resistant polymers can enable its application in this sector. This Project proposes a study of the production of polymeric compounds from the plasticization of orange residues with glycerol and subsequent incorporation into PLA by means of double-screw extrusion. The optimization of the glycerol content and plasticized residue in PLA will be carried out according to a central rotational composite design (DCCR), having as its dependent variables the mechanical, rheological and physicochemical properties. Finally, soil mass loss tests will be conducted in order to investigate the behavior of post-consumer materials.