HIGH CONVERSION COPOLYMERIZATION OF FURFURYL METHACRYLATE AND N-VINYL-PYRROLIDONE - A KINETIC APPROACH TO SKEISTS TREATMENT FOR FREE-RADICAL COPOLYMERIZATION IN DIFFERENT REACTION MEDIA

The influence of reaction conditions and temperature on the free radic al copolymerization of furfuryl methacrylate with N-vinylpyrrolidone, initiated by 2,2'-azobisisobutyronitrile (AIBN) is studied. The initia tion step is promoted by the thermal decomposition at 50-degrees-C of the AIBN molecules in N,N-dimethylformamide (DMF) solution or photoche mically at 0 and 40-degrees-C in bulk. The variation of the average co mposition of copolymer chains with the conversion for two different co mpositions of the monomer feed, f(F)o = 0.02 and 0.50, is analysed fro m the classical integrated copolymerization equation. Since the reacti vity ratios of this pair are very different, r(F) = 3.92 and r(P) = 0. 004, a simplified approximation of the integrated Skeist's equation is proposed. The experimental data obtained under different experimental conditions fit adequately the theoretical predictions, suggesting tha t the reaction medium (solution or bulk) or initiation technique (ther mal or photochemical) do not affect the average composition of the cop olymer chains at different conversions. However, the variation of the cumulative composition of copolymer chains with the degree of conversi on is very sensitive to the initial composition of monomer feed. In ad dition, the average rate of copolymerization seems to be also dependen t on the feed composition.