Effect of fiber length and volume fraction on the mechanical properties of jute fiber reinforced polypropylene composite

Abstract

This research work comprises of experimental determination and theoretical prediction of the effect of reinforcing fibre volume fraction and the mean reinforcing fibre length on the mechanical properties of short jute fibre reinforced polypropylene composite. Jute fibre reinforced polypropylene composites were prepared with extrusion compounding and injection moulding techniques. Moisture removal or drying was done at different stage of composite fabrication. In the present research, Mechanical behaviour (fracture resistance, tensile properties, critical reinforcing fibre length and the mean interfacial shear strength) of short-jute-fibre reinforced polypropylene composites was studied as a function of fibre volume fraction and fibre length. The values of the tensile strength, tensile modulus, failure strain and notched charpy impact energy were obtained from each group of ten specimens. To predict the tensile behaviour of short jute fibre reinforced polypropylene, the effect of the variation of reinforcing fibre length and volume fraction on the tensile strength, young's modulus and failure strain was investigated. Tensile tests were conducted following ASTM Standard and each test was preformed until tensile failure occurred except IOO%.polypropylene. The addition of jute fibres effectively enhances the ultimate tensile strength and modulus. The tensile strength of the composites increases with the increase of fibre loading up to the fibre volume fraction 25%, beyond which tensile strength decreased or no significant improvements were observed. A maximum of II% increase in strength and 163% increase of tensile modulus was observed. The highest tensile strength (33.733 MPa) is obtained from 25% jute fibre loaded polypropylene composite and the reinforcing fibre length is 2 mm. Tensile strength showed an increasing tendency with longer reinforcing fibre length. Fracture resistance being given by the specific work of fracture (WOF) or fracture toughness, here viz the Notched Charpy Impact Energy of the composites were investigated with a charpy impact tester on specimens with V-notches according to ASTM Standard. Introduction of reinforcement effectively enhance the impact strength of the composite but increasing reinforcement is insignificant. Matrix material and single fibre properties were investigated. Tensile modulus showed a decreasing tendency with the increasing reinforcing fibre length.