TENSILE PROPERTIES OF SURFACE TREATED COIR FIBRE REINFORCED POLYETHYLENE

Abstract

The need to pursue an environmentally safer future has prompted the researchers to look beyond the inorganic fibre-based composites and engage in putting more thought into the utilization of natural fibre-based polymer composites. Although inorganic fibres, such as glass and carbon have a lot of advantages but we can owe its declining use in recent years to high initial cost, non-biodegradability, non-renewability, high energy consumption in manufacturing process and adverse environmental impacts. Natural fibres however more than compensate for their poor compatibility with the matrix, inherent high moisture absorption rate with their positive attributes like low cost, low density, non-abrasivity, good thermal properties, enhanced energy recovery and bio degradability. This work is aimed at investigating the effect of alkali treatment and fibre load on the tensile properties and hardness properties of coir fibre reinforced polypropylene composites. Polypropylene (PP) was used as the matrix resin and coir fibre (CF) as the reinforcing agent. The brown coconut fibres were pulled out and extracted manually from the coconut husks. To ensure proper interaction between fibre and matrix material, the outermost wax layer of the coir was removed by soaking the coir in hot water. The coir fibres are then prepared for treatment with NaOH solution to improve its surface properties and provide better adhesion with the matrix after the removal of lignin and pectin from the surface of the fibre. The tensile properties indicated that both the strength and modulus increased with increasing fibre content. However, in this investigation, the maximum fibre content is 20%. It could have been more than this but we encountered processing problem. Alkaline treated samples had higher tensile properties than untreated samples. The hardness of the material is not significantly affected by the surface treatment.