Performance of short noil hemp fibre polypropylene composites

Abstract

In this study, short noil hemp fibre composite with varying fibre content were fabricated using intermixer and injection moulding machines. The maleic anhydride grafted polypropylene (MAPP) and maleic anhydride grafted Poly (ethylene octane) (MAPOE) were used as coupling agents for modifying the matrices. Tensile, dynamic mechanical and microstructural characterizations were performed by tensile strength testing, scanning electron microscope (SEM) and X-ray microtomography. The composites revealed better temperature resistance at higher fibre content. However, the increase in storage modulus and tensile strength was negligible in composites reinforced with more than 40 wt.% hemp fibres; due to the agglomeration of the fibres. The results also indicated that the tensile strength of the noil hemp fibre reinforced composites without a coupling agent was below the tensile strength of pure polypropylene. However, the addition of coupling agents improved the tensile strength of the noil hemp fibre reinforced polypropylene composites by increasing the reinforcing effects of the fibres due to the enhanced fibre/matrix interfacial adhesion. This was also confirmed by dynamic mechanical analysis. X-ray microtomography study concluded that coupling agent addition can also reduce the fibre breakage due to the better fibre dispersion in the polypropylene