Processing rigid wheat gluten biocomposites for high mechanical performance

Recently, unidirectional rigid gluten biocomposites have received attention because the glassy gluten matrix has comparable properties as an epoxy resin. This research proposes some possibilities to facilitate such biocomposites. The dry method is modified by using water exposed fibers rather than dry ones. The wet method uses an ethanol solution to suspend and partly dissolve original or milled gluten particles, in which the fibers are subsequently immersed. Drying impregnated fiber mats obtained via either the modified dry or wet method leads to prepregs of which stacks were compression molded into composites without the need for any further solvents or plasticizers. Gluten composites made by the wet method give much higher moduli and strengths compared to when using either of the dry methods. Using aqueous ethanol helps to dissolve part of the gluten (the gliadin fraction) and is believed to lead to a good wetting of the matrix between the fibers.