Mechanical and Biodegradation Behavior of Natural Fiber Composites

Abstract

This paper deals with the characterization of high strength and functional natural fiber reinforced composite materials which are fabricated using starch-based biodegradable resin and Manila hemp fiber. Hemp fiber reinforced cross-ply composites were prepared by a conventional hot-pressing method. Their mechanical characterization was carried out by evaluating tensile strength as a function of fiber content. It can be seen that the tensile strength of the cross-ply composites was saturated over 50 wt% due to the interaction between warp and weft during the hot-pressing. However in the case of flexible weft; such as cotton thread or resin fiber, the tensile strength of the cross-ply composites almost linearly increased with increasing fiber content. The biodegradation behavior of the hemp fiber reinforced unidirectional composites was also examined by burying them into compost media. The changes in surface morphology of the specimen and in specimen weight loss were monitored for 30 days. It is apparent that the natural fiber reinforced composites showed an enhanced biodegradation speed. This enhanced biodegradation behavior seems to be derived from increased apparent surface area of the composite specimen due to the preferential biodegradation at interface between hemp fiber and biodegradable resin as well as the preferential water transportation through internal cavity in hemp fiber.