Study on Mechanical Properties and Water Absorption Behaviour of Wastepaper Fibre/Recycled Polypropylene Composites

There has been growing interest in the use of waste materials as an alternative source for the conventional wood-plastic composites (WPC) in the global market. This paper evaluates the feasibility of two different kinds of wastepaper fibre as reinforcing materials used for WPC. For this purpose, the fibre morphology of old newspaper fibre (ONPF) and old magazine paper fibre (OMGF) was investigated by fibre morphology analyzer, respectively. Wastepaper fibres, recycled polypropylene (rPP), and 2%MAPP were compounded by double-roller mixer and test specimens were prepared by hot press moulding. The tensile, flexural, and water absorption properties of ONPF and OMGF reinforced rPP composites as a function of fibre content were studied. The results showed that the highest mechanical properties of ONP and OMG fibre reinforced composites could be reached with 30 wt.% fibre contents. The mechanical properties of the composites made from ONP fibres were better than those made from OMG fibres. However the addition of wastepaper fibres resulted in a decrease in elongation at break. Both the fibre loading and the fibre morphological characteristics had an effect on the water uptake behaviour. But the effect of fibre size on the water uptake was minimal compared to that of the fibre content. The water uptake of wastepaper fibre/rPP composites may actually be slowed down rather than delayed. Scanning electron microscopy (SEM) of the fracture surface of a tensile specimen with 30 wt.% wastepaper fibre loading showed good fibre dispersion in the matrix and a good compatibility between wastepaper fibre and rPP matrix. The results suggested that both the ONP fibres and the OMG fibres could be used as potential sources and reinforcing agent for composites, but the reinforcement effect of ONPF was better than that of OMGF.