A novel route for injection moulding of long carbon fibre-reinforced LLDPE

Abstract

The scope of our work has been the development of a new type of coupling agent by which processing of long carbon fibre-reinforced thermoplastic composites by conventional injection moulding can be possible. The experimental additive was expected to hinder fibre breakage and to simultaneously improve the mechanical properties of the composites. Resistance of LLDPE reinforced with 1–10 wt% long carbon fibres against tensile, flexure and impact stresses has been investigated. Tensile strength of carbon fibre/LLDPE composites has increased by 10–30%; flexure strength has gained 15–90% related to the neat polymer depending on the fibre concentration. The effect of a blowing agent on the mechanical properties has also been investigated. At least 20% higher yield strength has been measured for the foamed sample with 5% carbon fibre related to the nonfoamed one with the same fibre content. The higher the fibre content was, the higher the improvements in the mechanical properties became. Fibre–matrix interaction has been studied on scanning electron microscopy graphs where a well-connected polymer layer has been observed to the fibre surface.