Preparation and properties of PVC composites filled with walnut shell powder hybrid attapulgite.

In order to reveal the effect of alkali treatment of walnut shell (WS) powder and attapulgite (ATP) hybrid filling on the properties of WS/polyvinyl chloride (PVC) composites, and to compare the effects of different reinforcement methods, WS/PVC composites were prepared by single screw melt extrusion. Furthermore, analysis was conducted on the chemical composition, thermal stability, microstructure, and physical, mechanical and wear resistance properties of composites. The results showed that ATP hybrid can enhance the performance of WPC more effectively than alkali treatment, unmodified WS blended with ATP composites have the best physical, mechanical properties, abrasive wear resistance, as well as lower water absorption, compared with the untreated, the tensile strength, bending strength and impact strength increased by 24%, 8%, and 21%, respectively. In addition, the composites of ATP hybrid alkali treated WS have the best thermal stability, and its pyrolysis residue is 15.64% higher than untreated composites. The study found that ATP have a larger potential to enhance the properties of composites than alkali treatment. Highlights: Chemical treatment and inorganic mineral particle filling were used to enhance the properties of the WS/PVC composites.The experimental results showed that attapulgite can maximize the properties of the composites without alkali treatment. This means that attapulgite filling is a more effective and environmentally friendly and simple method to enhance the properties of composites than alkali treatment.The wear failure modes of the composites are mainly micro‐indentation and micro‐cutting. [ABSTRACT FROM AUTHOR]