Study on the Properties of Esterified Corn Starch/Polylactide Biodegradable Blends

Fully bio-based and biodegradable starch/polylactic acid blends have received increasing attentions for their biodegradability and potential to offset the use of unsustainable fossil resources, specifically, their application in packaging. Herein, corn starch was first esterified with maleic anhydride and then compounded with polylactide (PLA) to prepare esterified corn starch/polylactic acid blends with starch content up to 35 wt%. The structures, morphologies, thermal and mechanical properties of starch or blends were investigated. The results showed that corn starch was successfully grafted with maleic anhydride, which showed increased crystallinity and particle size than native starch. Esterified corn starch/polylactic acid blends showed good surficial compatibility and good thermal stability with main decomposition temperature in the range of 300°C to 400°C. Additionally, incorporation of corn starch increased the hydrophilicity and water uptake of composites. However, the tensile and flexural strengths of blends decreased with increasing esterified starch amount.