Preparation, characterization, and thermal behavior of MMA– N ‐aryl maleimide copolymers

The work describes the synthesis and characterization of copolymers of methyl methacrylate (MMA) and N ‐ o ‐tolyl maleimide (MO)/ N ‐ p ‐tolyl maleimide (MP)/4‐maleimido benzoic acid (MB). The copolymers were synthesized by varying the mol fraction of N ‐aryl maleimides from 0.1 to 0.5 in the initial feed using azobisisobutyronitrile (AIBN) as an initiator and tetrahydrofuran as the solvent. The copolymer composition was determined from the 1 H‐NMR spectra by taking the ratio of proton resonance signals due to OCH 3 of MMA (δ=3.59 ppm) and the aromatic protons (δ=7.0–7.3 ppm) of N ‐aryl maleimides. The monomer reactivity ratios of MMA–MP were r 1 =0.926±0.001 and r 2 =0.47±0.03 and MMA–;MO were r 1 =1.37±0.005 and r 2 =0.31±0.01. The initial decomposition temperature of copolymers and glass transition temperatures increased with increasing N ‐aryl maleimide content in the backbone. © 1994 John Wiley & Sons, Inc.