Degradation kinetics of acrylonitrile/methyl vinyl ketone copolymers

Methyl vinyl ketone (MVK) was first used to successfully copolymerize with acrylonitrile (AN). This was achieved by using azobisisobutyronitrile as the initiator. Differential scanning calorimetry results of the degradation of AN/MVK copolymers in air are presented. The apparent activation energy of degradation of the copolymers was calculated with Kissinger method. Effects of copolymerization conditions on the apparent activation energy of the copolymers were studied. It has been found that increasing dimethyl sulfoxide concentration in the solvent mixture leads to a rapid increase in the degradation apparent activation energy of AN/MVK copolymers. The apparent activation energy decreases quickly along with increase in the comononer MVK concentration, and this change becomes less prominent as the weight ratio of MVK/AN goes beyond 7/93. The apparent activation energy shows a trend of increase as the copolymerization temperature increases. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1386–1390, 2007