CMRG Examines Pultruded Composites Reinforced with Natural Fibers

Materials Research Group (CMRG) at the University of Mississippi (UM) have recently begun a research study supported by the U. S. Department of Agriculture (NRICSREES-USDA Award number 2003-35504-13627) examining natural fiber reinforcements (NFR). The objectives of this research are to demonstrate the feasibility of using the cost-effective pultrusion process to manufacture high quality polymeric composites using natural fiber reinforcements, to publish details concerning pultrusion using NFR in the open literature, and to quantify mechanical property variability for these composites. The initial pultrusion experiments conducted for this study utilized hybrid reinforcement composed of E-glass with unidirectional hemp yarn or woven hemp mat reinforcements. As society begins to recognize the importance of utilizing renewable bioproducts that are beneficial to the environment, focus is beginning to return to agricultural materials. In this study, the use of agricultural products as constituent materials in composites is being reexamined, and new technology is being applied to efficiently utilize these materials. Agricultural crop fibers such as flax, kenaf, hemp, jute, and sisal have the potential to act as replacements for glass fiber reinforcements in polymeric composites. Influenced by environmental concerns, the European automotive industry has been a leader in the commercialization of natural fiber composites in applications such as door panels, interior trim parts, structural headliners, and seat backs. This trend is now being adopted by the North American automotive industry. In addition to the automotive applications that have been commercialized, research work continues worldwide on the utilization of agricultural fibers as a substitute for glass fibers for applications with more demanding property requirements. In general, natural fibers offer moderate mechanical properties, but, in some aspects, the properties of natural fibers can surpass those of E-glass. The acoustic insulating properties of the fibers are especially desirable for some applications. The low density (ρ) of natural fibers makes them competitive and even superior to E-glass in terms of specific strength (σ/ρ) and Mississippi Pultrusion