The morphology and strength of cassava starch-based biofoam with ZnO addition

Styrene is a plastic-type that is used as a heat-insulating material for buildings with properties difficult to be degraded, so that, this plastic should be reduced in utilization with an alternative biofoam. This study aims to present the influence of ZnO reinforcement on morphology and strength of cassava starch-based biofoam. The experiment started with biofoam synthesis using baking methods method. Biofoam made of cassava starch containing the ZnO of 0%, 3%, 6%, 9%. The resulting biofoam was observed using a scanning electron microscope and tensile test. The result indicates that the morphology of biofoam without the addition of ZnO had cavities with thick inter-cavity walls, while biofoam with variations of the addition of 3%, 6%, and 9% ZnO formed relatively the same cavities with thinner inter-cavity walls when compared to biofoam without ZnO addition. The highest strength value occurred in biofoam with the addition of 6% ZnO resulting in an average tensile strength of 0.9283 MPa. Nonetheless, when the ZnO content exceeded 6%, as demonstrated by the addition of 9% ZnO, the tensile strength of the biofoam declined to 0.7544 MPa.