Methyl methacrylate/N-(o-/m-/p-chlorophenyl) itaconimide copolymers:: Microstructure determination by NMR spectroscopy

Homopolymerization and copolymerization of N-(o-/m-/p-chlorophenyl) itaconimide with methyl methacrylate was carried out by taking varying mole fractions (0.1 to 0.5) of N-aryl substituted itaconimide monomers in the initial feed using azobisisobutyronitrile as an initiator and tetrahydrofuran as the solvent. The copolymer composition was determined by H-1-NMR spectroscopy using the ratio of proton resonance signal intensity attributed to -OCH3 of MMA (delta = 3.5-3.8 ppm) and the aromatic protons (delta = 7.0-7.5 ppm) of N-(o-/m-/p-chlorophenyl) itaconimide. The comonorner reactivity ratios were determined using Kelen-Tudos and nonlinear error in variable methods. The reactivity ratios obtained by nonlinear error in variable methods were r(1) (PI) = 1.26/r(2) (MMA) = 0.35; r(1) (MI) 1.21/r(2) (MMA) = 0.34; and r(3) (01) = 0.78/r(2) (MMA) 0.34. The carbonyl carbon signals of MMA (M) as well as N-aryl itaconimide (1) copolymers were used for the determination of the sequence distribution of M- and I-centered triads. The sequence distribution of M- and I-centered triads determined from C-13{H-1}-NMR spectra of the copolymers are in good agreement with the triad concentrations calculated using the Alfrey-Mayo statistical model and Monte Carlo simulation method. (C) 2003 Wiley Periodicals, Inc.