Waste Dimer Acid‐Based Plasticizer for Polylactic Acid

ABSTRACT Petroleum‐based plasticizers, typified by dioctyl terephthalate (DOTP), pose tremendous environmental risks primarily through bioaccumulation in aquatic organisms. Waste dimer acids (WDAs), byproducts of dimer acid production from vegetable oils, are nontoxic, biodegradable, and low cost. In this study, epoxy waste dimer acid methyl ester (EWDAM) was synthesized by a novel esterification and epoxidation process and subsequently blended with polylactic acid (PLA) to create an environmentally friendly material. EWDAM was synthesized through a two‐step process involving the esterification of WDA with methanol catalyzed by P‐toluene sulfonic acid, followed by the reaction of the intermediate with formic acid and hydrogen peroxide. The modified PLA demonstrated significantly enhanced mechanical properties, including an elongation at break of 72.6% and an impact strength of 8.2 kJ/m 2 , compared to neat PLA. These results demonstrated that EWDAM imparts a plasticizing effect comparable to DOTP, improving flexibility and processability. The modified PLA demonstrates enhanced suitability for biodegradable packaging, agricultural films, and other plastic applications. This study presents a sustainable approach to converting industrial waste WDA into high‐value plasticizers for PLA, offering a green alternative to conventional petroleum‐based plasticizers such as DOTP. This strategy addresses both the brittleness of PLA and the environmental concerns linked to traditional plasticizers.