SBIR Phase I: Natural Fiber-Reinforced Bio-Based Thermoset Resin Composites

This Small Business Innovation Research Phase I project will develop natural fiber-reinforced bio-based resin composites that are appropriate for use in exterior applications on vehicles (automobiles, over-the-road trucks, and recreational vehicles). These bio-based engineering materials are interesting to automotive and truck manufactures because of their light weight, potential low cost, and low environmental impact. However, these composites tend to be highly sensitive to moisture. That sensitivity is one of the main barriers to commercialization for bio-based composites. Currently, no natural fiber-reinforced composites are used as structural components in transportation applications because of the moisture sensitivity issue. The approach is to investigate combinations of fiber type, fiber processing, and resin chemistry to produce composites with strong interfacial bonding and properties that are the least sensitive to moisture. It will be determined how the type of fiber (kenaf vs. flax), the processing of the fiber (degree of fibrillation, and surface modification), and the type of resin (soybean oil-derived resins vs. modified phenolics) affect the mechanical properties of the composites and their moisture sensitivity. It is anticipated that within this experimental space will be combinations that produce good interfacial bonding between resin and fiber which will lead to reduced moisture sensitivity. Natural fibers and bio-based resins have the potential to replace fiberglass and synthetic resins derived from petroleum in a variety of composite applications. The most likely opportunities will be in the transportation sector (automotive, truck, RV); additional opportunities may develop in building materials (subfloor, roof, decking, posts and beams). Replacing fiberglass-reinforced synthetic resin composites with natural fiber-reinforced biobased thermoset resin composites will have the many advantages over traditional composites. The bio-based composites will have lower density, acceptable specific strength, equal or higher specific modulus, and fibers that are non-abrasive and have low wear rates for tooling. Their environmental impact will be less as the are renewable resources and use less non-renewable energy in making the fibers. There will be a weight reduction which can increase fuel economy and reduce emissions as well as reduce the life-cycle environmental impact by sequestering carbon during the growth of the plant material. This product will have a lower cost due to the fact that these are renewable resources and have a lower cost of raw materials at industrial production levels. Natural fibers and bio-based resins can be combined with synthetic fibers and resins to provide design flexibility, e.g., if the stiffness of a natural fiber-reinforced composite is insufficient for an application, fiberglass (10-30 wt%) can be added to raise the modulus to an acceptable level. One still realizes much of the value of the natural reinforcement. Likewise, bio-based resins can be used to extend petrochemical resins much as ethanol is blended with gasoline.