Exploring the role of cardanol acetate and epoxidized cardanol acetate as plasticizers in polylactic acid blown films

Abstract Polylactic acid (PLA) is a promising biodegradable material for packaging, but its limited ductility restricts its use. Blending PLA with flexible polyesters can improve ductility but often reduces transparency. To address this, two plasticizers derived from the natural phenolic compound cardanol (CD)—cardanol acetate (CA) and epoxidized cardanol acetate (ECA)—were synthesized to enhance PLA's ductility without compromising transparency. PLA films were plasticized with varying concentrations of CA and ECA using melt mixing‐extrusion. The results showed that ECA significantly improved PLA's flexibility and compatibility due to the interactions between its epoxy groups and PLA's carboxyl end groups. PLA‐15ECA exhibited a tensile strength of 41.9 MPa and a remarkable elongation at break of 336.6%, compared to pure PLA's 52.1 MPa and 13.7%, respectively. Transparency was maintained (transmittance >85%), and thermal stability was excellent, with only a 2% mass loss after 2 h at 200°C. This study highlights the potential of using natural plasticizers to improve PLA's performance for eco‐friendly packaging applications. Highlights Synthesize cardanol‐based plasticizers for PLA's ductility and transparency. Plasticizer active‐group reactivity and solubility are key to PLA modification. PLA‐15ECA has a tensile strength of 41.9 MPa and an elongation at break of 336.6%. ECA ‐ plasticized PLA films balance strength, toughness, and keep transparency.