Wheat gluten based materials have become the focus of considerable interest. Recently, gluten has been mixed with plasticizers like glycerol to make rubbery gluten polymers. The drawback of this type of material is the expense of the modulus and strength. The same phenomenon was observed for gluten composites when gluten was plasticized and then mixed with fibers to obtain rubber-like composite materials. As an alternative, gluten has been either dissolved in meta-cresol or semi-plasticized by water, to obtain rigid gluten composites. However, all these results show lower moduli than theoretically expected. Therefore, obtaining high mechanical performance for this sort of rigid polymer and composite materials still poses challenges.

In this research, rigid gluten polymers and composites have been studied. The first results showed that the moisture absorption strongly affected on the mechanical properties of the polymers. Interestingly, at standard storing conditions, the mechanical properties of gluten polymers are quite comparable with a benchmark epoxy resin. In addition, first developments were done in the processing of unidirectional natural fiber composites with a gluten matrix, which gave considerable improvement in modulus and strength compared to gluten composite materials described in literature.