Preparation and mechanical properties of pithecellobium clypearia benth fibre/polypropylene composites processed by vane extruder

Pithecellobium Clypearia Benth fibre (PCBF) comes from steam-exploded Chinese medicine residue was filled in polypropylene (PP) matrix to prepare for PCBF/PP composites using vane extruder based on elongational deformation. The testing technologies related to the structure and morphology of PCBF with different times of steam explosion treatment were conducted by nuclear magnetic resonance (NMR), automatic surface area analyser and scanning electron microscopy (SEM). The effects of different times of steam explosion treatment, PCBF content, coupling agent content and extruding speed on the comprehensive mechanical properties of PCBF/PP composites were studied in this paper. The results showed that the PCBF has a higher content of cellulose, an increased aspect ratio and an enlarged specific surface area after third time steam explosion treatment. The tensile strength, tensile modulus, flexural strength and flexural modulus of PCBF/PP composites increase with the increasing times of steam explosion treatment when the times not more than three, and then decrease with increasing times of steam explosion treatment when the times exceed three. The tensile properties and flexural properties of PCBF/PP composites change with the increasing of PCBF content, coupling agent content and extruding speed nonlinearly. Furthermore, the SEM of PCBF/PP composites showed better interfacial interaction between the fibre and the matrix.