Preparation and properties of wheat gluten/methylcellulose binary blend film casting from aqueous ammonia: A comparison with compression molded composites

The present work focused on the preparation and properties of wheat gluten (WG)/methylcellulose (MC) blend films containing 25 wt% glycerol plasticizer. Morphology, tensile properties (Young’s modulus E, tensile strength σb and elongation at break εb), and water vapor permeability (WVP) were evaluated in relation to MC to total polymer ratio, xMC. Mechanical properties of compression molded WG/MC composites were also investigated for comparison. Experimental results reveal that the casting films are superior in mechanical properties to the molded composites. The casting blend films show tailored mechanical and moisture barrier properties. Increasing xMC can improve E, σb and εb simultaneously but lower moisture barrier performance at low relative humidity.