5-chloro-8-quinolinyl acrylate and N-vinyl-2-pyrrolidone copolymers: Synthesis, characterization and complexes with poly(methacrylic acid)

New copolymers of 5-chloro-8-quinolinyl acrylate (AQ) and N-vinyl-2-pyrrolidone (VP) were obtained by radical copolymerization in benzene or in DMF. Values of reactivity ratios for VP (M(1)) and AQ (M(2)) were r(1) = 0.11 and r(2) = 0.35 according to the Fineman-Ross method and 0.09 and 0.29 according to the Kelen-Tudos method, respectively. The product of the reactivity ratios, r(1) x r(2), was less than unity indicating a tendency towards alternation in the formation of copolymers. At considerable excess of VP and by the ''compensation'' method of polymerization, it was possible to obtain polymers, containing blocks of VP repeating units, It was shown that polymers with high VP content did not form interpolymer complexes in DMF with poly(methacrylic acid) and did not form interpolymer complexes with poly(acrylic acid). The polycomplexes were stable in the temperature range 20-80 degrees C. On increasing AQ content in the copolymers, the stability of the polycomplexes decreased and copolymers with AQ content higher than 30 mol% did not form interpolymer complexes.