Thermal Degradation of Epoxidized Soybean Oil in the Presence of Chlorine-Containing Polymers

The thermal degradation of epoxidized soybean oil has been examined using thermal and spectroscopic methods. In both the presence and absence of Cl containing polymers, epoxidized soybean oil undergoes thermal degradation to form ring-opened products. In the absence of other reactants, the primary degradation reaction is apparently intermolecular ether formation. The degradation in a highly-chlorinated polymer matrix (e.g. PVC) appears to be facilitated by reaction with hydrogen chloride generated by polymer degradation. Fully epoxidized soybean oil (7.0 wt.% oxirane oxygen) appears to contain two types of oxirane groups: type I which begins to undergo thermal ring-opening at approx 175 deg C and type II which opens at > 325 deg C. Both ring openings are exothermic and irreversible. Type I oxirane groups account for approximately one-third of the total content of fully epoxidized soybean oil. Partially epoxidized soybean oil (3.28 wt.% oxirane oxygen) contains only type II oxirane functionality. Graphs, Spectra. 17 ref.--AA