Reinforcing Effect of Kevlar 49 Fibre on the Mechanical Properties of Polypropylene

Abstract

It is common knowledge that Polypropylene can be reinforcedby using fillers, e.g. glassfibre, jutefibre, wood pulp, kenafand Kevlarfibresfor applications in the defence, automobile and engineering industries. Kevlar fibre has high strength to weight ratio, isthermally stable and highly resistant. Kevlar fibrecan be used as reinforcementto prepare advanced polymer compositeswith superior properties. In this study,the composites were fabricated by first melting the polymer pellets into films of 1 mm thick in a 100 mm x 100 mm mold, before stacking the polymer films and the woven Kevlar fabric and the whole arrangement preheated for 8 min before being pressed under 500 psi pressure at 190 oC for 4 min using compression molding technique, followed by cooling for 4 min under pressure followed by removal from the mold. The effect of Kevlar fibre loading (12% - 23%) onthe mechanicalproperties (flexural, impact and tensile strength as well as modulus) and morphology (interfacial bond)of polypropylene laminates fabricated by compression molding technique is reported. The reinforcementfibreincreases the tensile, flexural and impact strength of the composite as well as the tensile and flexural moduli, as the percentage Kevlar fibre loading increases. More so, Kevlar fibreinclusion did not significantly affect the density of the composite. The percentage Kevlar fibre incorporated into the polypropylene composites resulted in different morphologies as evident from the microscopic examination.