Toward reducing the food packaging waste impact: a study on the effect of Starch type and PE type in thermoplastic starch-polyethylene blends

One of the most feasible approaches that could be used to alleviate the extent of the environmental impact of polyethylene waste from sources like food packaging is adding a biopolymer such as starch to the polyethylene matrix. This work aims to investigate the effect of the PE type and the starch type on the properties of the blends. Two types of commercial starches, corn, and wheat were first plasticized by glycerol and water and then melt-blended with LDPE or LLDPE. The PE-g-MA was used as a compatibilizer. FTIR was employed to prove the formation of ester bonds between the thermoplastic starch and the compatibilizer. In addition to that, the morphology, thermal properties, mechanical properties, water intake, and biodegradability of the prepared blends were studied and compared. It was found that the presence of the compatibilizer had an essential impact on the thermal, mechanical, and morphological properties of polymer blends. Blends with LLDPE showed higher thermal and mechanical properties than blends with LDPE. The blend of TPWS with LLDPE had the highest mechanical properties compared with all other blends, with or without compatibilization. The degradation study by α-amylase enzyme showed no significant effect of the starch type or the PE type on the biodegradation rate of the studied blends.