acrylonitrile (AN)/ammonium acrylate (AAT) copolymers were prepared by H2O/dimethyl formamide suspension polymerization technique. Differential scanning calorimetry results of the degradation of AN/AAT copolymers in air are presented. The apparent activation energy of degradation of the copolymer was calculated by using Kissinger method. Effects of copolymerization conditions on the apparent activation energy of copolymer were studied. It has been found that increasing dimethyl formamide concentration in the solvent mixture leads to a rapid increase in the degradation apparent activation energy of AN/AAT copolymer. The value of the degradation apparent activation energy of the copolymer synthesized in dimethyl formamide solvent increases up to 141.7 kJ mol(-1). The apparent activation energy decreases quickly, along with increase in AAT concentration, and this change becomes less prominent as the weight ratio of AAT/AN goes beyond 6/94. The apparent activation energy shows a trend of increase with increasing copolymerization temperature. (c) 2006 Wiley Periodicals, Inc.