Studies on performance evaluation of a green plasticizer made by enzymatic esterification of furfuryl alcohol and castor oil fatty acid

•A plasticizer was synthesized from two bio-molecules, furfuryl alcohol and castor oil fatty acid, by enzymatic esterification.•The ester was applied into EC film to evaluate its efficiency as plasticizer and compared with a conventional one.•Mechanical performance of the ester in ethyl cellulose film showed good plasticizing property than the conventional one.•Ester containing EC film showed outstanding mechanical performances and thermal stability. The esterification of furfuryl alcohol (FA) and castor oil fatty acid (COFA) at 3:1 molar ratio, by immobilized Candida antarctica Lipase B (NS 435 from Novozyme) in a solvent free system gave a maximum yield of 88.64% (%w/w) at 5h. Performance of the FA-COFA ester plasticized Ethyl Cellulose (EC) films were evaluated by surface morphologies, XRD analysis, mechanical properties,thermal properties, water vapor permeability and migration stability test. It was an effective plasticizer with better mechanical properties and thermal stability at the increasing concentration of FA-COFA ester (15–25%) containing EC film, than the traditional plasticizer, i.e; dibutyl phthalate (DBP) in producing good quality films. Chemical structure and the intermolecular interactions between FA-COFA ester and ethyl cellulose chains were the causative agents of these outstanding performances. Therefore, this FA-COFA ester, with significant plasticizing property, at a certain concentration, can be a substitute of DBP.