Mechanism of stabilizing action of PMSya sulfonate additive

Abstract

In an investigation of the mechanism of stabilizing action of the calcium sulfonate additive PMSya, the following have been demonstrated: 1. With increasing concentration of PMSya in a suspension of kaolin in naphtha, the size of the clay-particle aggregates becomes smaller, and peptization sets in. 2. The adsorption of PMSya on the surface of kaolin particles takes place in two stages, i.e., chemisorption and reversible adsorption. 3. The optimum condition for formation of the stiffest precipitate from the suspension, with a maximum volumetric solids content, is the presence of hydrophobic and hydrophilic sections on the kaolin particle surface in a certain ratio that is achieved by incomplete adsorption of the PMSya by the kaolin, equivalent to approximately 50% of the maximum possible adsorption. 4. Smaller quantities of active ingredient and the presence of “mechanical, admixtures” in the additive will reduce its stabilizing action, so that greater consumption of additive is required for hydrophobization of the clay particles.