Assessment of Epoxidized\nIsobutyl Fatty Esters from\nSoybean Oil Distillates as Biobased Plasticizers

This study evaluated the production and performance of\nbiobased\nepoxidized isobutyl esters (EIE) as sustainable plasticizers for polymers,\naiming to support circular economy models within the chemical industry.\nEIE were synthesized through the esterification of isobutyl alcohol\nwith oleic and linoleic acids as well as soybean oil deodorizer distillates\n(SODD), followed by subsequent epoxidation. The plasticizing effect\nof epoxidized isobutyl oleate, linoleate, and soyate was assessed\nby studying their mechanical and thermal properties and performing\nDynamic Mechanical Analysis (DMA) on PVC films prepared at a fixed\ncontent of 70 phr using the solvent casting method. The chemical structure\nof the films was identified by Fourier transform infrared (FTIR) spectroscopy\nwhile the permanence of the plasticizers was investigated through\nmigration and volatility tests. Finally, barrier properties such as\nwater vapor permeability and migration were evaluated alongside surface\ncharacteristics such as contact angle and transparency by UV–visible\nspectroscopy. Dioctyl phthalate (DOP) and epoxidized soybean oil (ESO)\nwere used as reference commercial plasticizers. Among the different\nEIE, epoxidized isobutyl soyate (EIS) showed remarkable results such\nas high elasticity (500%), high thermal stability, tensile strength\n(11.2 MPa) comparable to the reference plasticizers, and high plasticizing\nefficiency (106.2%). However, barrier properties, such as water vapor\npermeability and migration, were affected by the composition of this\nepoxidized ester. Overall, EIE exhibited moderate migration rates\nwhich limit their use as general purpose PVC plasticizers, but they\nmight be effectively used for low temperature applications and as\ncoplasticizers for different polymers.