Alkylethoxyethanesulphonates: Two techniques for improving synthetic conversions

Abstract

Alkylethoxyethanesulphonates, high‐cost speciality surfactants, are most commonly synthesized from precursor ethoxyalcohols by thionyl chloride chlorination followed by sulphonation with sodium sulphite. Conversions in the sulphonation stage are only moderate with highly hydrophobic ethoxychlorides. Alkylethoxyalcohols with a novel narrow distribution of ethoxy chain lengths recently have been reported. We demonstrate how the conversion in the sulphonation of hexadecanol tetraethoxychloride increases from 65% to 80% when the traditional broad ethoxylate distribution ethoxyalcohol is replaced by narrow range ethoxyalcohol as precursor. Replacement of sodium sulphite by potassium sulphite increases conversion still further, to quantitative, in the sulphonation of the narrow range ethoxychloride. Exploitation of these two techniques in the manufacture of ethoxyethanesulphonate surfactants might be expected to improve the economics of their application.