Analysis of polyethylene glycol esters

Abstract

Summary The products obtained by esterification of polyethylene glycols with fatty acid, or by means of the reaction of ethylene oxide with fatty acids, can be analyzed for their content of monoester, diester, and unreacted polyethylene glycol by taking advantage of the extractability of the polyethylene glycol with water. A hot salt solution is used to insure selective extraction. Saponification and hydroxyl numbers are used to calculate the composition of the mixture; the molecular weights of the acid and glycol are presumed to be known.