Enhancing the reactivity of soybean oil toward free-radical cures

“Soybean oil is high in polyunsaturates and is classified as a semi-drying oil. However, this unsaturation in soybean oil is not enough to readily produce a highly cross- linked polymer via free-radical polymerization. This study utilizes different reactions to further increase the unsaturation in the soybean oil structure, in hopes of making it more reactive towards free-radical polymerization. The final goal of the study is to produce a highly cross-linked, rigid polymer via free-radical polymerization from treated soybean oil. This study was divided into two approaches. In the first approach, soybean oil was first treated by halogenation. The halogenated derivatives were then dehydrohalogenated to attempt to produce more unsaturation in the chains. NMR spectroscopy was used to verify the quantity of unsaturation in the treated soybean oil. Also a technique was investigated to produce a cross-linked, rigid polymer by treating the halogenated soybean oil with a strong base like zinc oxide in a hot press at 400F. The cross-linked nature of the polymer was tested by solubility test and percent soluble impurity in the cross-linked polymer was found by soxhlet extraction using THF as the solvent. In the second approach, soybean oil was reacted with N-bromosuccinimide in order to provide low, but constant, concentration of bromine. This approach is a single step process. Though the number of double bonds in the treated soybean oil remained approximately the same as in the raw soybean oil, NMR spectral analysis depicted the shift in the position of double bonds in treated soybean oil and also indicated the presence of conjugated double bonds, which are more reactive towards free-radical polymerization”--Abstract, page iii