FEATURES OF RADICAL COPOLYMERIZATION OF W ATER-SOLUBLE MONOMERS

The radical copolymerization reactions of acrylamide (AA) with N-vinyl pyrrolidone (VP) in water and DMSO were studied by NMR and Raman spect roscopies. The compositions of copolymers were determined at various d egrees of conversion, and reactivity ratios were calculated. For the A A-VP copolymerization in water, the reactivity ratios calculated at sm all conversions are r(1) 1.2 +/- 0.2 (for AA) and r(2) 0.8 +/- 0.2; in DMSO, both constants are equal to unity. The composition of copolymer s formed during the copolymerization in an aqueous solution did not va ry until about a 70% conversion was reached. An analysis of the presen t results and previous data on the copolymerization of AA with other w ater-soluble monomers in aqueous solutions shows that the lack of depe ndence of the copolymer composition on conversion is a specific featur e of systems under consideration, which is caused by hydrophobic inter actions in aqueous polymer solutions.