Free radical meleation of soybean oil <Emphasis Type="Italic">via</Emphasis> a single-step process

In this study a new value-added product was developed from soybean oil for use as a chemical feedstock. The investigation and optimization of this work resulted in a fast and simple process to maleate soybean oil. An anhydride functionality was introduced into soybean oil through a free radical-initiated maleation. Two initiators were evaluated, 2,5-bis(tert-butylperoxy)2,5-dimethylhexane peroxide and di-tert-butyl peroxide. The effects of reaction time, initiator concentration, maleic anhydride concentration, and reaction temperature were investigated. The maleated soybean oil was characterized using acid value, iodine value, and FTIR spectroscopy. The acid value was directly related to the initial concentration of maleic anhydride, whereas the concentration and type of initiator had little effect on the acid value. The peroxide-initated functionalization of soybean oil with maleic anhydride in a closed vessel at elevated pressure and temperature was found to proceed by a Diels-Alder mechanism.