Polymer cation effect on the stability to electrolytes of an ethanol-acrylate methacrylate—water, coacervated system

Abstract

Colloidal, aqueous dispersions of certain acrylate-methacrylate copolymers with cationic groups have been prepared by a coacervation technique using ethanol as solvent and water as nonsolvent. Stability of the dispersions to electrolytes (sodium chloride, sodium sulfate, and sodium carbonate) increased markedly (up to 10 times) with a small (2-fold) increase in polymer cation content. The polymer dispersions were most sensitive to sodium sulfate and least sensitive to sodium chloride. Sodium carbonate was, in turn, less effective than the sulfate in flocculating the dispersions; this observation relates to the partial hydrolysis of the CO₃ ^2- anion to less readily adsorbed OH⁻ and HCO₃ ⁻ anions.