The Use of Rice Husk Ash as a Reactive Filler in the PSO/EP Resin Composite for Potential Automotive Applications

The research studies about the development and characterization of a rice husk ash (RHA)-reinforced polysulfide oligomer/epoxy resin (PSO/EP) composite for use in automotive applications. To improve mechanical and chemical properties, RHA is a silica-rich agricultural byproduct which was incorporated at different loadings (0.5,1, 2 wt%). The composite was prepared using a modified thiokol method for PSO and with universal EDP-2 epoxy resin which was supplied by Altai Prom Polymer. Many characterizations have been done. Crosslinking between the thiol groups of PSO and epoxy resin was confirmed by FTIR analysis, while XRD showed a hybrid structure that was primarily amorphous polymer networks and crystalline silica from RHA. SEM showed a consistent RHA distribution with strong adhesion between the filler and matrix. Mechanical testing demonstrated optimal performance at 1 wt% RHA, providing a tensile strength increase of 5% and a flexural strength increase of 49% compared to unfilled epoxy, due to RHA’s ability to transfer stress. Increased RHA loadings (2 wt%) caused agglomeration and reduced strength. The composite demonstrated good thermal stability, resistance to automotive fluids, and low VOC emissions. Windshield adhesives (with a shear strength enhancement), underbody coatings (which offer corrosion resistance through RHA’s SiO₂ barrier), and engine gaskets (with a compression set of less than 10%) are all potential automotive applications. RHA is underscored in the research as a sustainable, inexpensive filler that reconciles flexibility (PSO) and rigidity (EP), providing a practical substitute for synthetic fillers in lightweight automotive parts.