Bioplastics from Blends of Cassava and Rice Flours: The Effect of Blend Composition

Bioplastics from melt-mixing of cassava flour, rice flour and their blends with compositions of between 0/100 and 100/0 %wt were successfully obtained using twin-screw extrusion and compression molding processes. The influence of blend composition on the bioplastic's properties was studied. It was found that the flour blends were uniformly mixed. The tensile properties and dynamic properties of the flour bioplastics were examined. The tensile strength and storage modulus of compression molded bioplastics based on rice flour was greater than those of the cassava flour, but their flexibility was lower. The tensile strength and storage modulus of the flour blend bioplastics increased with increasing rice flour content The flour bioplastics showed two glass transitions, one corresponding to glycerol rich phase and the other corresponding to plasticized starch. For plasticized flour blends, the glass transitions were not affected by the blend composition. The improvement in the mechanical properties of the bioplastics produced from the cassava/rice flour blend could be explained by an increase in the crystallinity level resulting from the higher concentration of rice flour. Using flour blends derived from cassava and rice flours, the bioplastics developed in this study offer a greater performance while maintaining environmental compatibility and sustainability, which allows for a substitution of tradition bioplastics from cassava starch.