Kinetic study of radical polymerization v. determination of reactivity ratio in copolymerization of acrylonitrile and itaconic acid by H-1-NMR

摘要

Many reports exist in the literature about the application of H-1 and C-13-NMR techniques to analyze the copolymer structure and composition and also determination of reactivity ratios. In this work, on-line H-1-NMR spectroscopy has been applied to identify reactivity ratios of itaconic acid and acrylonitrile in the solution phase ( DMSO as the solvent) and in the presence of AIBN as the radical initiator. All the peaks corresponding to the existing protons were assigned quietly. Therefore, the kinetics of the copolymerization reaction was investigated by studying the variation of integral of two characteristic peaks regarding each monomer. The obtained data were used to find the reactivity ratios of acrylonitrile and itaconic acid by linear least-squares methods such as Finemann-Ross, inverted Finemann-Ross, Mayo-Lewis, Kelen-Tudos, extended Kelen-Tudos and Mao-Huglin. In addition, a non-linear least-square method (Tidwell-Mortimer) was used at low conversions. Extended Kelen-Tudos and Mao-Huglin were applied to determine reactivity ratio values at high conversions as well.