Thermal and mechanical behaviour of Phormium tenax reinforced polypropylene composites

Composites of Phormium tenax fibres in a polypropylene matrix with fibre content up to 40 wt%, produced by injection moulding and twin screw compounding, have been characterized by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis and mechanical test. The results have shown that the main degradation peak for polypropylene was slightly shifted to higher temperatures with increasing content of fibres, thus improving the thermal stability of the composites. The introduction of fibres did not result in a significant variation in the position of the peaks for calorimetric analysis, except for the melting peak, which appeared lower for the composites with respect to the neat matrix. A slight increase in crystallinity was also measured. Tensile modulus has been increased by reinforcing the matrix with growing amounts of fibres, whilst the effect on tensile strength was not evident.