Method to Produce Polyhydroxy Carboxylic Acid Esters of Polyethylene Glycol

A method to produce polyethylene glycol (PEG) ester comprises the step of reacting PEG with polyhydroxy carboxylic acids or estolides of polyhydroxy fatty acids at a temperature of 120°C to 200°C in the absence of any catalysts. The lack of a catalyst prevents over oxidation and unwanted side-products and the need to remove the catalyst at the end of the process. The PEG preferably has an average molecular weight of 200-2000, more preferably 200-300. The estolide is preferably a diestolide or a triestolide. Preferably, the polyhydroxy carboxylic acid has at least 2 hydroxy groups on adjacent carbon atoms. Preferably, the polyhydroxy carboxylic acid is a fatty acid, more preferably 9,10-dihydroxystearic acid (DHSA). In another aspect, a DHSA PEG ester and its use as a surfactant in a toiletry composition.