SEDL / STP / STP1328-EB / STP13842S

Hydrolytic Stability of Phosphate Ester Surfactants

Anderson, DG
Manager of Analytical Sciences, Oleochemicals/Surfactants Group, Witco Corporation, Chicago, IL

Eberle, WJ
Scientist and Scientist II, Ciba Crop Protection, Ciba-Geigy Corporation, Greensboro, NC

Stubbs, DR
Scientist and Scientist II, Ciba Crop Protection, Ciba-Geigy Corporation, Greensboro, NC

Pages: 16    Published: Jan 1997

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Abstract

The unique properties of phosphate ester surfactants make them highly functional components in a multitude of formulations throughout the agricultural industry. Synthetic routes leading to the formation of phosphate esters are relatively well understood. The formation of mono-, di-, tri- and pyrophosphate ester species, however, varies considerably with reaction conditions and stoichiometry. Historically, the analysis of these mixtures has centered around the potentiometric titration of acidic species to determine the concentration of the various phosphate ester species present. The information obtained using this approach can be misleading and fails to provide the comprehensive characterization possible using through the application of state-of-the-art analytical methodology; including ³¹P nuclear magnetic resonance spectroscopy, high performance liquid chromatography and capillary electrophoresis. These techniques will be compared relative to the examination of phosphate ester surfactants. Specifically prepared phosphate esters were studied for hydrolytic stability at ambient and elevated temperature. Little evidence for hydrolysis was observed past seven days exposure, with minor effects noted due to temperature and water concentration.