Abstract
Tung oil fatty acid ethyl ester, which contained eleostearate in 80 per cent, was diluted with ethyl myristate and heated to cyclize with 0.2wt% sulfur at 160, 220 and 290°C. The yield of cyclic monomer was very higher than that of the cyclization without sulfur. Then thermal treatment of tung oil fatty ester, ethyl oleate and ethyl elaidate with sulfur were analysed by ESR respectively to examine the effect acid ethyl of sulfur. It was found at least that sulfur catalyzed random cis-trans isomerization, i.e. in cyclization trans double bond between 11 and 12 carban of eleostearate was isomerized to cis form remarkably by sulfur.
