Abstract: | This study describes the synthesis, characterization, and thermal behavior of copolymers of methyl methacrylate (MMA) and N‐p‐tolyl itaconimide (PTI)/N‐phenyl itaconimide (I). Homopolymerization and copolymerization of N‐(phenyl/p‐tolyl) itaconimide with MMA was carried out by use of various mole fractions of N‐aryl itaconimide in the initial feed from 0.1 to 0.5, using azobisisobutyronitrile as an initiator and tetrahydrofuran as the solvent. The copolymer composition was determined by 1H‐NMR spectroscopy using the proton resonance signals attributed to –OCH3 of MMA (δ = 3.5–3.8 ppm) and the aromatic protons (δ = 7.0–7.5 ppm) of N‐aryl itaconimide. The reactivity ratios of the monomers were found to be r1 (PTI) = 1.33 ± 0.05/r2 (MMA) = 0.24 ± 0.03 and r1 (I) = 1.465 ± 0.035/r2 (MMA) = 0.385 ± 0.005. The molecular weight of the copolymers decreased with increasing mole fraction of N‐aryl itaconimide in the copolymers. Glass‐transition temperature (Tg) and thermal stability of PMMA increased with increasing amounts of itaconimides in the polymer backbone. A significant increase in the percentage char yield at 700°C was observed on incorporation of a low mole fraction of N‐aryl itaconimides. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1195–1202, 2003 |