Influence of filler content and mixing time on the properties and morphology of kenaf/polyurethane foam composites

Abstract

Kenaf/polyurethane foam composites were prepared at percentage of 2, 4, 6 and 8 wt% of kenaf fiber. Free rising polyurethane foam was prepared at constant (NCO/OH) ratio 1.5:2, while water was used as blowing agent. The mixture was stirred at 400 rpm using mixing times of 20 and 25 seconds. Rise time and hardness of the composites was determined. From the results obtained, rise time and hardness of polyurethane foam composites were reduced at 25s mixing time. However, as kenaf core fiber increase, the rise time decreased and the hardness of the foam composite increased. The Scanning Electron Microscopy (SEM) analysis evidenced the presence of regular cell shape and uniform cell size in the kenaf/polyurethane foam composites. The findings indicate the potential of using kenaf fiber to enhance the properties of the polyurethane foam.