Copolymerization of sodium salt of 2-acrylamido-2-methylpropanesulfonic acid with acrylamide in water-dimethyl sulfoxide solutions

The kinetics of homogeneous free-radical copolymerization of acrylamide (M-1) and sodium salt of 2-acrylamido-2-methylpropanesulfonic acid (M-2) carried out at pH 9 and 50degreesC in the presence of potassium peroxosulfate in water, a water-DMSO (20 : 80) mixture, and DMSO was studied. When DMSO was used instead of water, the initial rate of copolymerization and the reaction orders with respect to comonomers (M-1, M-2) and the initiator increase, the amount of M-2 units in the copolymer grows, and its molecular mass decreases. The experimental evidence is interpreted with regard to the effects of solvents on the state of ionogenic groups of monomer M-2 and growing chains, the character of electrostatic interactions between reacting species, and the formation of intermolecular hydrogen bonds between the solvent and M-2 and (growing chains) in the course of copolymerization.