Marine Degradation and In Vitro Biodegradation of <scp>PLA</scp>‐<scp>TPS</scp> Blends

ABSTRACT In this study, poly(lactic acid) (PLA) and thermoplastic starch (TPS) with chain extender and compatibilizer are prepared by twin screw extrusion. The compounds are thermally compressed at 185°C using a square mold. The blends are subjected to marine degradation and in vitro biodegradation techniques based on solid‐state and liquid‐state fermentations by fungi and bacteria. The performance of PLA and PLA‐TPS blends under marine conditions is evaluated in terms of mechanical and thermal properties. The results show that this material is not biodegradable in marine conditions due to PLA content and needs specific conditions for biodegradation. However, the solid‐state assay gives a visual answer to the question of biodegradability, since fungal or bacterial growth translates to the sample being used as a carbon source. In addition, the liquid‐state fermentation provides quantitative results for biodegradation, expressed as percentage, biomass, residual mass, and protein secretion. These techniques may offer insight into the potential of materials to be considered biodegradable or compostable. The duration of the experiments is significantly lower (6 days) than that reported in the literature and the standardized tests (90 days).