Effect of Fiber Ratio and Chemical Treatment on Properties of Banana and Betel Nut Fiber Reinforced Hybrid Polypropylene Composites

Abstract

The term hybrid composite refers to the composite containing more than one type of fiber material as reinforcing fillers. It has become attractive structural material due to the ability of providing better combination of properties as compared to single fiber composite. In present research, banana and betel nut fiber reinforced polypropylene composites were prepared by hot pressing technique. Raw banana and betel nut fiber were chemically treated with sodium hydroxide to increase adhesion of those fibers with polypropylene. Both raw and alkali treated fibers at 15 wt% were utilized during composite preparation. Banana and betel nut fiber ratios were varied at 1:1, 3:1 and 1:3. Scanning electron microscopic and thermogravimetric analysis, mechanical (tensile, flexural, impact and hardness) and water absorption tests of prepared composites were subsequently conducted. According to microscopic analysis, composites containing treated banana and betel nut fiber at 3:1 ratio had the best adhesion between the fibers and matrix. Polypropylene composites reinforced with banana and betel nut fiber 3:1 ratio had highest tensile and flexural properties, while composites reinforced with banana and betel nut fiber 1:3 ratio showed highest impact properties. According to water absorption test, higher banana fiber containing composite had higher water absorption as compared to higher betel nut fiber containing composite. Polypropylene composites reinforced with equal amount of banana and betel nut fiber had highest thermal stability among all prepared composites. Sodium hydroxide treatment of fibers increased flexural and hardness properties of composites as compared to raw fiber composites. On the other hand, opposite trend was observed in case of tensile, impact and water absorption properties.