Vegetable oil based rigid foam composites

Rigid polymeric foams reinforced with natural or synthetic fibers constitute a major class of semi-structural composite materials. With the existing emphasis shifting from petroleum-based resources towards renewable resources, and sustainable engineering and materials, the usage of vegetable oils for producing biopolymers and resins through chemical syntheses is ever increasing. For rigid-foam composites, the usage of vegetable-oil-based, polyether- and polyester-urethane resins bring about a predominant renewable fraction. The degree of renewability in rigid foam composites is further increased by the addition of a natural fiber/filler, such as flax fiber or hemp fiber, which with exceptions, always cause increased mechanical performance over their unreinforced foam counter-parts. Production of these rigid foam composites is dependent upon the fiber content and the specific foam type, with reaction injection molding (RIM) and mold casting positioned as leading production methods. Many industrial sectors have been penetrated by rigid foam biocomposites, chiefly marine and construction, but a major market for these materials is the transportation industry, which harnesses the superior mechanical performance, cost-effectiveness, and biorenewability of rigid-foam biocomposites in many underbody applications