One step beyond for CNSL-based plasticizers for PVC: Use of cardol

Abstract

Poly(vinyl chloride) (PVC) is a widely employed plastic across diverse industries and is often associated with plasticizers, additives that decrease the inherent rigidity and brittleness of the material. Conventional phthalate-based plasticizers raise substantial toxicity concerns, encouraging the exploration of bio-based alternatives. One such alternative is the inedible oil, cashew nutshell liquid (CNSL), mainly composed of cardanol and cardol. Recent efforts have focused on developing a cardanol-based PVC plasticizers but the isolation of cardanol involves time-consuming, energy-intensive, and costly steps, limiting its market competitiveness. This study aims to assess for the first time, the efficiency of cardol esters, synthesized using acetic acid and different fatty acids (octanoic acid and myristic acid), in order to evaluate the influence of the alkyl chain on plasticizer properties. The chemical structures of these plasticizers were fully characterized by ¹H NMR spectroscopy, and the mechanical properties and thermal behavior of PVC films plasticized with these additives were investigated. Finally, the endocrine activity was evaluated for cardol and cardanol acetates.