The effect of itaconic acid (IA), atmosphere and heating rate on the thermal stabilization of acrylonitrile copolymer with itaconic acid [P(AN-IA)] was studied by differential scanning calorimetry (DSC), showing that IA could significantly reduce the initiation temperature of the exotherm, and decrease the quantity and the rate of heat evolved in the DSC exotherm. The initiation temperature of the exotherm of P(AN-IA) was little influenced by the atmosphere, however, distinctly decreased with the enhancement of IA content in the copolymer, which implied that the initiation of nitrile cyclization reaction preceded the onset of oxidation reaction through an ionic mechanism. Promoting heating rate resulted in a shift of the exotherm to a higher temperature, and a more rapid liberation of heat. The activation energy was calculated with the Kissinger method, and the results showed that IA could efficiently decrease the activation energy.

Key words: differential scanning calorimetry, thermal stabilization, polyacrylonitrile, itaconic acid