Toughened wheat gluten and treated coconut fiber composite

The aim of the present work is to fabricate a biodegradable composite with improved mechanical properties and high work to failure by combining toughened wheat gluten matrix with 15 mass% surface treated, highly ductile coconut fiber. Matrix cracking at a flexural stress of 46 MPa in wheat gluten was delayed until nearly 71 MPa in the composite, with ultimate stress greater than 105 MPa. Flexural stiffness was improved from roughly 4 GPa in the wheat gluten to 5.4 GPa in the composite. The work to failure was improved from 0.26 MJ/m3 in wheat gluten to 1.45 MJ/m3 with the toughened wheat gluten, and finally to 4.94 MJ/m3 for the composite. The toughening additive for the wheat gluten was shown to “erase” aging effects in the wheat gluten but also appeared to change the interfacial characteristics.