Mechanical Properties and Kinetics of Thermal Degradation of Bioplastics based on Straw Cellulose and Whole Wheat Flour

During the past two decades the use of bioplastics, as a suitable alternative to petroleum-based plastics, has attracted researcher's attention to a great extent. In this study, the whole wheat flour and straw cellulose at different proportions were mixed with glycerol and bioplastics sheets were obtained by a press type molding machine. The mechanical properties of samples were examined on compositions prepared by whole wheat weight in three proportions of 70, 60 and 50% and the cellulose in three proportions 75, 70 and 65%. The tensile tests on the samples indicated that with lowering proportions of both flour and cellulose, the modulus of elasticity and tensile strength of the bioplastics dropped as well. The maximum modulus of elasticity achieved for the flour and cellulose compositions were 12.5,and 8.6 MPa, and the maximum tensile strengths were 878 and 202 kPa, respectively.The TGA tests indicated that the bioplastics prepared from whole wheat flour showed higher temperatures of thermal degradation. The activation energies calculated for the flour and cellulose bioplastics, as estimated by Arrhenius type equation, were 133.0 and 63.8 kJ/mol, respectively.