ENVIRONMENTAL DURABILITY OF NATURAL FIBER REINFORCED UNSATURATED POLYESTER COMPOSITE

With an industrial increasing interest in sustainable, eco-efficient and green material's application, natural fiber in polymer composite is guided to develop rapidly, especially kenaf nonwovens in making automotive interior trim parts with its comparative excellent strength and renewability. The objectives of this research are to investigate the environmental degradation behavior on the physical and mechanical properties of kenaf/unsaturated polyester nonwoven composites (KUNC) with special reference to the influence of different geographic natural climate ageing conditions. KUNC was prepared with needle-punched kenaf's impregnation into unsaturated polyester resin assisted with vacuum oven following by hand lay-up molding. Natural environmental degradation was performed on KUNC by exposing the specimens to Kyoto(Japan), Shanghai(China) and Harbin(China) for a period of 3 months. Weight change and mechanical properties of degraded KUNCs in former three geographic positions in terms of tensile, flexural, impact and fracture toughness were measured instrumentally for ageing effect discussion and comparison. As expected, the aged specimens in those different positions all showed the dropped mechanical properties with weight increasing in varying degrees. Furthermore, the result of degradation level comparison among different positions revealed the positive correlation between increased weight percentages and dropped mechanical properties. In other words, dropped mechanical properties of the degraded composites with increasing weight were attributed to the effect of water, which deteriorates the interfacial properties of composites.