Studies on the copolymerization of methyl methacrylate with N-(o/m/p-chlorophenyl) itaconimides

The article describes the synthesis and characterization of N-aryl itaconim ide monomers such as: N-(p-chlorophenyl) itaconimide (PI)/N-(m-chlorophenyl ) itaconimide (MI)/N-(o-chlorophenyl) itaconimide (OI) and its copolymeriza tion behavior with MMA. The homopolymers and copolymers of N-aryl itaconimi des and methyl methacrylate (MMA, M-2) were synthesized by varying the mol fraction of N-aryl itaconimides in the initial feed from 0.1 to 0.5 using a zobisisobutyronitrile (AIBN) as an initiator and tetrahydrofuran (THF) as t he solvent. Copolymer composition was determined using H-1-NMR spectroscopy [by taking the ratio of intensities of signals due to -OCH3 of MMA (delta = 3.59 ppm) and the aromatic proton (delta = 7.2-7.5 ppm) of N-aryl itaconi mides] and percent nitrogen content. The reactivity ratios were found to be r(1) = 1.33 and r(2) = 0.36 (PI-MMA) r(1) = 1.15 and r(2) = 0.32 (MI-MMA) and r(1) = 0.81 and r(2) = 0.35 (OI-MMA). Molecular weight as determined us ing high-performance liquid chromatography decreased with increasing mol fr action of itaconimides in copolymers. All the polymers had a polydisperstiv ity index in the range of 1.5-2.6.Thermal characterization was done using d ifferential scanning calorimetry and dynamic thermogravimetry in nitrogen a tmosphere. Incorporation of these N-aryl itaconimides in PMMA backbone resu lted in an improvement in glass transition temperature (T-g) and thermal st ability, Percent char increased with the increase of PI/MI/OI content in th e copolymers. (C) 2001 John Wiley & Sons, Inc.