Investigation on mechanical, wear and thermal stability of cardanol oil bio-toughener, palm kernel fiber, and chitosan reinforced polyester resin composite at aging conditions

The development of science technology, growing demand for producing sustainable compounds in material science, has promoted newer innovations such as producing lightweight biocomposite material. The present study also aims to investigate the mechanical, wear, and thermal stability properties of bio-oil toughened polyester matrix reinforced under palm kernel fiber and chitosan biopolymer. Furthermore, for understanding the overall performance of the composite, and the durability of the material over a period of time, the present study examined the composite strength after the aging process, which is treating under varying atmospheric conditions, and it brings a novelty to this study. The chitosan is rich in amine groups, which promote the mechanical strength of the material, and it is bio-extracted from sea urchin species using alkali and acid treatment. Further, for promoting toughness and stiffness properties to the composite, the cardanol oil is blended with resin matrix. Finally, using those raw materials, the composite material is prepared under the hand layup method. The result of the study demonstrated that the addition of chitosan biopolymer of 3 vol.%, fiber of 40 vol.%, and cardanol oil of 20 vol.% on the composite PC5 shows better mechanical, wear, and thermal stability behavior when compared to aged composite material. The study findings concluded that the tensile and flexural strength of aged composite PC5 is 20% reduced strength when compared to unaged composite material. Further, the increase chitosan of 5 vol.% in composite (PC6) exhibited a COF of 0.45 and a specific wear rate of 0.005 mm³/Nm, representing reductions of 43.75% and 85.71%, respectively, compared to PC0. The thermogravimetric analysis (TGA) further highlighted the thermal stability improvements, with chitosan-reinforced composites exhibiting the highest resistance to thermal degradation. PC6 retained 80% of its weight at 500 °C compared to only 20% for the plain resin. The fatigue properties also followed a similar trend, with PC5 demonstrating fatigue lives of 20 × 10³ cycles at 25% UTS, 18 × 10³ cycles at 50% UTS, and 16 × 10³ cycles at 75% UTS, indicating significant improvements over the plain resin. Thus, the overall study of the composite shows that reinforcement of kernel fiber, chitosan, and cardanol oil into the composite shows superior mechanical, wear resistance, and thermal stability properties; however, the composite under aging drops in strength property, and it is considerable. Due to such superior strength, wear resistance, and corrosive resistance even under the aging process, the biocomposite is applied in housing kitchens, washtubs, turbine blades, windmill sectors, interior door panels automotive, aviation sector, etc.