Synthesis of Bio-Plasticizer from Soybean Oil and Its Application in Poly(Vinyl Chloride) Films

Herein, epoxidized soybean oil methyl ester (ESOM) plasticizer was synthesized for the preparation of plasticized poly(vinyl chloride) (PVC) films by the alcoholysis and epoxidation. The chemical structure of ESOM was investigated by infrared spectrum and H-1 nuclear magnetic resonance. The effect of content of ESOM and petroleum based plasticizer di-2-ethylhexyl phthalate (DEHP) on the performance of plasticized PVC films was studied. The result showed that substituting DEHP with ESOM can improve the thermal stability of plasticized PVC films. When the weight ratio of ESOM and PVC is fixed at 1:2, plasticized PVC film presents higher elongation at break (350.8% vs. 345.1%) and lower tensile strength (14.21 MPa vs. 15.8 MPa) compared with PVC plasticized with DEHP. ESOM showed less weight loss than DEHP in all solvents. The excellent migration resistance of ESOM is helpful to improve stability of plasticized PVC films. In all, the obtained bio-based plasticizer will be potential to replace petroleum based plasticizer DEHP in flexible PVC materials.