Neutralization of Basic Oil-Soluble Calcium Sulfonates by Carboxylic Acids

Publisher Website
Google Scholar
Abstract
Correlations between aggregate structure and reactivity for basic oil-soluble calcium sulfonates may be determined through room temperature neutralization in heptane using low molecular-weight carboxylic acids; the reaction was followed by infrared spectroscopy. If hexanoic acid was used, it was possible to selectively neutralize and measure both the hydroxide and carbonate base present within the aggregate core. Unexpectedly large amounts of carboxylate salts from the neutralization (calcium hexanoate) are solubilized within the sulfonate micellar aggregate core, up to a maximum hexanoatel sulfonate molar ratio of 5:1. The results indicate that hydroxidic base in these aggregates is easily accessible through neutralization by simple organic acids and that this base most probably is located within the outer regions of the aggregate core.