Degradation behavior of biocomposites based on cassava starch buried under indoor soil conditions

•Biocomposite films were prepared from tapioca starch by casting method.•Degradation behavior of biocomposites was studied under indoor soil conditions.•Experiments were performed according to Box–Behnken experimental design.•Effects of process variables on the degradation behavior were studied.•Second order polynomial models were developed from the experimental data. Degradation of cassava (tapioca) starch based composite films during indoor soil burial experiments was analyzed using five factors, three levels Box–Behnken response surface design. From the results, it was observed that, increased water sorption promotes the entry of soil microorganism and it utilizes the starch films as a source of energy for their growth. The reduction in weight and mechanical property was associated with preferential loss of matrix components of the films. The microorganisms associated with the degradation of films were quantified and identified. Scanning electron microscopy (SEM) analysis showed the formation of patterns and cracks on the surface of the materials aged in the soils. From the results, second order polynomial models were developed for the responses. The results of the study demonstrated that, the tapioca starch based composites were showed a limited lifetime in biotic environment which make them suitable for being disposed in landfills after their use.