Preparation of Natural Fiber Kenaf Composite and Its Properties through Graft Polymerization Method

摘要

The present study is aiming to find the optimal condition of methyl methacrylate (MMA) graft polymerization onto natural kenaf fiber and exploring the use of grafted kenaf fiber in PMMA-based thermoplastic composite. The results of the study show that the effect of pretreatment time, the important of cerium concentration and the role of the reaction time are significantly affect the graft yield of MMA monomer onto kenaf fiber in a positive trend. This graft polymerization technique was intended to be used to alter hydrophilic feature of natural kenaf fiber in order to increase the compatibility with the polymer matrix material. In order to examine the applicability of the grafted kenaf as the reinforcement of composite material, the grafted kenaf with graft yield of ca. 160 % was prepared in a large-scale experiment. The grafted kenaf fiber and PMMA powder were dry-blended so the mixture contains 60 wt% PMMA in total composition and have molded into composite plates by hot-pressing method. The composite plate with using untreated kenaf fiber was also prepared for the comparison. The essential characteristic of the composites such as mechanical properties and water absorbency were evaluated. Confirmation of the improved interfacial adhesion between the fiber and the matrix was also discussed. From these results, it could be concluded that the modification of natural kenaf fiber by graft polymerization method can effectively improve the poor adhesion between PMMA matrix and kenaf fiber and provide better characteristics of the natural fiber based composite material.