Valorization of Prickly Pear Seed and Olive Husk Agricultural Wastes for Plastic Reinforcement: The Influence on the Mechanical and Thermal Properties

Abstract

AbstractCurrently, food waste is a major concern for businesses, governments, and consumers. Fruit processing creates many of by‐products, from undesirables to fruit skins, seeds, and fleshy parts. These by‐products make up to 30% of the initial mass of processed fruit. This goal can be achieved by transforming fruit waste into reinforcement and integrating it into polymeric materials. In this work, olive husk flours (OHF) and prickly pear seed flours (PPSF) are used as reinforcements of poly (lactic acid) (PLA) matrix. Initially, the physico‐chemical, particle size, spectroscopy (FTIR), and thermal characterization of its fibers are studied and compared. Then, the composite materials studied are manufactured with a twin‐screw extruder having a fiber content of 10%, 20%, and 30% by weight; its properties have been studied and compared. The characterization of these two fibers shows that the quantity of cellulose is greater in the OHF and that the latter is more thermally stable. For the composite material, the PLA /OHF are the most responsive in thermal and mechanical behaviors since their degradation temperatures are closer to pure PLA and the tensile modulus is higher compared to the PLA/PPSF composites. The equilibrium water uptake value is higher for composites reinforced with OHF than systems with PPSF.