Free-radical solution copolymerization of Nphenyl methacrylamide and methyl methacrylate in various feed ratios was done using a benzoyl peroxide initiator in N,N-dimethylformamide at 70degreesC. The structure of the copolymer was elucidated by infrared and proton nuclear magnetic resonance spectroscopy. The copolymer composition was determined from the corresponding H-1-NMR spectra of the copolymers. Finemann-Ross and Kelen-Tuclos methods were used to determine the reactivity ratios of the monomers. The molecular weight distribution of the copolymers was determined using gel permeation chromatography. Thermal properties of the copolymers were determined using differential scanning calorimetry and thermogravimetric analysis (TGA). The activation energy for thermal degradation of the copolymers was determined from the TGA data. (C) 2003 Wiley Periodicals, Inc.