Determination of degradation rate of acrylonitrile polymers



Low-temperature degradations of acrylonitrile homopolymers and acrylonitrile/acrylamide copolymers in air were investigated by IR and thermogravimetry. The degradation rates of acrylonitrile polymers were determined by measurement of normalized absorbance of [BOND]C[TRIPLE BOND]N band and effects of the degradation temperature, time, and comonomer on the rate of degradations were discussed. It was found that the polymers start to degrade as the temperature increased to 150°C. In the temperature range of 180–210°C, values of the rate of polymer degradation were maximal and the rate of degradation of acrylonitrile/acrylamide copolymers was higher compared with that of acrylonitrile homopolymers. At 150°C, acrylonitrile homopolymers had an induction period of about 0.5 h. The rate of degradation of acrylonitrile/acrylamide copolymers showed an obvious trend of increase along with acrylamide concentration, and changes of the rate became less prominent as the weight ratio of acrylamide/acrylonitrile went beyond 5/95. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1511–1514, 2006