Synthesis and Characterization of Novel Surfactants Based on 2‐Hydroxy‐4‐(Methylthio)Butanoic Acid: 1. Anionic Surfactants |
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| Authors: | Guangzhe Yu Scott A. Long Kyle A. Karinshak Brian P. Grady Jeff H. Harwell Graciela B. Arhancet |
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| Affiliation: | 1. , Institute for Applied Surfactant Research and School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK, USA;2. Novus International Inc., St. Charles, MO, USA;3. 405‐325‐4369 |
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| Abstract: | 2‐Hydroxy‐4‐(methylthio)butanoic acid (HMTBA) is a commonly used animal feed additive available in large quantities. In this study, anionic surfactants were synthesized utilizing HMTBA as a starting material. Specifically, a straight‐chain fatty acid containing 12 or 16 carbon atoms was attached to the hydroxyl group via esterification. After neutralization of the carboxylic acid with sodium, the molecules behave as anionic surfactants. Oxidation of the sulfur atom can be performed to further increase water solubility. The molecules exhibit critical micelle concentrations (CMCs), and lower the surface tension to 35–45 mN/m at the CMC. The derivatives have low Krafft points (<4 °C) and good wetting performance. The hardness tolerance of the ester made from dodecanoic acid is ～2.5–4 orders of magnitude higher than an analogous carboxylate surfactant, namely sodium dodecanoate. Foam created according to the Ross‐Miles foam test is substantial, but dissipates quickly as compared to other anionic surfactants. |
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| Keywords: | Surfactant Anionic Sulfoxide Ester Carboxylate |
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