Fabrication and characterization of high filled tea oil camellia shells/polypropylene composites: Effect of high filler and maleic anhydride grafted polypropylene

Abstract Tea oil camellia shells (TOCS), a significant biomass waste with an annual production exceeding 3 million tons in China, are increasingly being employed as industrial raw materials. In this study, TOCS/polypropylene composites with high filler contents (50–90%) were fabricated using an extrusion pelletizing‐hot pressing method, with 5% talcum added as an additional filler. The results indicated that the composites with 90% filler content exhibited the highest residue, and the composites containing 50% filler demonstrated the highest tensile strength and flexural strength. Although the 24‐hour water absorption and thickness swelling rates increased with higher filler content, the incorporation of maleic anhydride grafted polypropylene (MAPP) significantly enhanced the water resistance of the composites. Specifically, the 24‐hour thickness swelling rate of composites with 80% filler and 18% MAPP was controlled at 6.03%. Additionally, the maximum flexural modulus was achieved with the composites fabricated by 80% filler and 12% MAPP. Microscopic analysis revealed that the addition of MAPP facilitated the formation of a cross‐linked network structure between the TOCS fibers and the polypropylene matrix. Cost analysis demonstrated that increasing the filler content in the composites can substantially reduce material costs, thereby offering a product with improved economic efficiency. Highlights Fabrication of up to 90% filled TOCS/polypropylene composites. MAPP inhibited the thickness swelling of the composites when absorbing water. Insights for low‐cost biomass composites production.