Copolymerization of sodium 2-crylamido-2-methylpropanesulfonate with sodium acrylate in concentrated aqueous solutions

Abstract

The kinetic features of potassium persulfate-initiated homogeneous radical copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate (M1) with sodium acrylate (M2) in concentrated aqueous solutions and NaCl aqueous solutions at pH 9 and T = 60°C have been studied. The initial rate of copolymerization increases with the concentration of each monomer, the total concentration of comonomers (M1 + M2), the concentration of initiator, and the concentration of NaCl and shows an extreme change with an increase in the content of M2 in the initial monomer mixture. The molecular mass of the copolymer shows an extreme dependence on the content of M2 in the initial monomer mixture; it drops with an increase in the concentration of NaCl and remains unchanged with conversion. For copolymerization in water and 2 M NaCl, r2 > r1. The number of M2 units in the copolymer does not change with conversion and increases on addition of NaCl owing to a gain in r2.