Characterization and treatments of pineapple leaf fibre thermoplastic composite for construction application

Abstract

In recent years natural fibres appear to be the outstanding materials which come as the viable and abundant substitute for the expensive and nonrenewable synthetic fibre. Natural fibres like sisal, banana, jute, oil plam, kenaf and coir has been used as reinforcement in thermoplastic composite for applications in consumer goods, furniture, low cost housing and civil structures. Pineapple leaf fibre (PALF) is one of them that have also good potential as reinforcement in thermoplastic composite. It is the objective of the current research to characterize PALF and to investigate the effect of fibre treatment on the mechanical properties of PALF reinforced polypropylene (PP) composite. PALF was prepared from raw pineapple leaf. It was then chemically treated to hinder the water content. Both PP and PALF were compounded using two-roll mill machine prior to compression moulding via hot press machine to form a sheet. After forming the composite sheet, samples were prepared for tensile test (ASTM D638), flexural test (ASTM D790) and impact test (ASTM D256). Scanning Electron Microscope (SEM) was used to investigate the miscibility between the fibre and matrix. It was found that PALF contain 87.56% holocellulose, 78.11% alpha cellulose, 9.45% hemicellulose and 4.78 % lignin. The chemical constituents obtained were in the range to data reported in literatures. It was also observed that the flexural modulus and strength of treated PALF reinforced PP composite increased linearly with increment of fibre loadings. This trend was similar for impact strength where it exhibited a slight reduction at the initial stage but increased later as the fibre loading increased. The study has demonstrated that the optimum fibre loading for the best performance of the composite achieved was 30 wt%. This was clarified further by SEM where fibres and matrix have shown better miscibility at 30 wt% of treated PALF.