Bio‐Based Epoxy Cardanol Butyrate Ester as a High‐Efficiency Plasticizer: Antimicrobial Performance and Low Migration

ABSTRACT A novel epoxidized cashew nut phenol derivative plasticizer (ECAE) was successfully designed and synthesized as a green, bio‐based alternative to conventional phthalate plasticizers. Cashew nut phenol was chemically modified via a two‐step reaction sequence involving esterification followed by epoxidation, yielding a multifunctional plasticizer that incorporated flexible long‐chain alkyl groups, ester functionalities, and epoxy groups. When blended with PVC, ECAE exhibited superior performance: a glass transition temperature of 28.10°C, elongation at break reaching 702.12% at 50 phr loading, and antibacterial activity with a 15 mm inhibition zone against Staphylococcus aureus . It also demonstrated excellent stability, with only 0.3% migration after 240 h in distilled water at 25°C. Quantum chemical calculations elucidated the plasticization mechanism, revealing how the combination of spatial effects from long‐chain alkyl groups and anchoring effects from polar functional groups modulates PVC chain segment dynamics. This bio‐based plasticizer represents a significant advance in sustainable polymer technology, meeting environmental requirements while maintaining high performance. It holds potential for applications in food packaging and medical device manufacturing, where material performance and safety are paramount.