Water-soluble polymers by interaction of sulfonic polyelectrolytes with dipolar aprotic solvents

The solution of the strongly acidic polyelectrolyte poly(2-acrylamido-2-methylpropanesulfonic acid) in N,N-dimethylformamide or N,N-dimethylacetamide is accompanied by a simultaneous reaction of amidation of the sulfonic acid to the corresponding sulfonamide groups. Various compositions of binary copolymers poly[(2-acrylamido-2-methylpropanesulfonic acid)-co-(2-acrylamido-2-methylpropane-N,N-dimethylsulfonamide)] up to high amidation conversions of 98-99% were synthesized and characterized. The amidation of the sulfonic acid groups appears to be a common reaction for different copolymers having 2-acrylamido-2-methylpropanesulfonic acid moieties but fails with the free monomer.