Concentration effect in copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate in aqueous solutions

The effect of the concentration of the initial monomer mixture, the comonomer ratio, and temperature on the kinetic parameters of the process and the characteristics of the resulting copolymers in the homogeneous copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate in aqueous solutions at 50–80°C in the presence of potassium persulfate is studied. The initial rate of copolymerization and the molecular mass of copolymers increase with the total initial concentration of the monomer mixture and the content of sodium 2-acrylamido-2-methylpropanesulfonate. As temperature increases, the initial rate of copolymerization increases and the molecular mass of the copolymer diminishes. When copolymerization is performed in 10, 30, and 40% aqueous solutions of the monomers, the resulting copolymers are enriched in sodium acrylate units. The content of sodium 2-acrylamido-2-methylpropane-sulfonate units in the copolymer slightly increases with an increase in the total initial concentration of the monomer mixture.