Effect of fibre ratio and chemical treatment on the properties of pineapple leaf and betel nut husk fibre-reinforced hybrid polypropylene composites

In present research, polypropylene composites were prepared with 10 wt% pineapple and betel nut fibres at ratios of 1:1, 1:3 and 3:1 using compression moulding technique. Both pineapple and betel nut fibre were chemically treated with 5% NaOH. Composite was then prepared with treated pineapple and betel nut fibre at a ratio of 1:3. Mechanical (tensile, flexural and hardness), thermal (thermogravimetric analysis) and morphological (scanning electron microscopy) characterisation of prepared composites were subsequently carried out. Among the fibre ratios, composites containing pineapple and betel nut fibre at a ratio of 1:3 had the best set of mechanical properties. Alkali treatment of pineapple and betel nut fibre decreased tensile and flexural properties of corresponding composites. On the other, the same treatment had opposite effect on hardness. According to scanning electron microscopic analysis, composite containing pineapple and betel nut fibre at a ratio of 1:3 showed more adhesion as compared to other prepared composites. Thermal degradation temperature decreased in alkali-treated fibre- reinforced composite.