Kinetic study of radical polymerization. IV. Determination of reactivity ratio in copolymerization of styrene and itaconic acid by H-1-NMR

摘要

Here, online H-1-NMR spectroscopy has been successfully applied to investigate the kinetic parameters of radical copolymerization of styrene (St) and itaconic acid (IA). This technique was used because it allowed us to individually map out the monomer conversions of St and IA during the course of the polymerization at various conversions. This was possible because the individual contributions to the overall monomer conversion from St and TA could be measured through their nonoverlapping vinylic proton signals. The results of monomer conversion during the time in the corresponding H-1-NMR spectra was the basis of our analysis to determine the reactivity ratios of St and IA in the solution and radical copolymerization reaction by several methods. In addition to linear least-squares methods, such as Finemann-Ross, inverted Finemann-Ross, Mayo-Lewis, Kelen-Tudos, extended Kelen-Tudos, and Mao-Huglin, a nonlinear least-square method (Tidwell-Mortimer) was used for this purpose, at low conversions. Extended Kelen-Tudos and Mao-Huglin were applied to determine the reactivity ratio values at high conversions too. (c) 2006 Wiley Periodicals, Inc.