Composition of methyl esters from heat‐bodied linseed oils

Abstract

Abstract Two heat‐bodied linseed oils, with Gardner viscosities of 37 and 55 min, were saponified, converted to their methyl esters, and separated into 2 fractions with urea and methanol. Gas‐liquid chromatography showed the adduct fraction, which comprised 38舑41% of the total methyl esters, to contain: palmitic, stearic, oleic, 舠linoleic,舡 and trace amounts of 舠linolenic舡 acid. The nonadducting fraction (59舑62%) of the total methyl esters was separated by molecular distillation at 140C/7 ॖ into a distillate and residue. The distillate amounted to 18舑25% of the total methyl esters and had an iodine value (I.V.) of 142舑145; its absorption at 232 mॖ indicates 2.5舑3.0% conjugated diene. Hydrogenation of this distillate gave a liquid product with an iodine number of 4 and a pour point of 蜢50C. Gas chromatograms of the distillate and its hydrogenated derivative indicated at least 5舑7 components. Comparison of these peaks with known fatty acid methyl esters indicates that the components of these fractions were either cyclic or branched esters. The nonadducting residue fraction was composed mainly of polymeric acids.