Sidney Straus

Thermal Degradation of Polyacrylonitrile, Polybutadiene, and Copolymers of Butadiene with Acrylonitrile and Styrene

Abstract Polybutadiene and a copolymer consisting of 76.5 per cent butadiene and 23.5 per cent of styrene were investigated as to the rate of their thermal degradation. The rates for polybutadiene indicated an activation energy of 62 kilocalories per mole. The copolymer had very high initial rates of degradation followed by a rapid drop, so that it was not possible to obtain a reliable activation energy. Polyacrylonitrile and a copolymer consisting of 31 per cent of acrylonitrile and 69 per cent of butadiene were investigated with regard to the nature and distribution of volatile products, as well as to the rates of their thermal degradation. The rates were very high initially, but dropped rapidly so that it was not possible to determine accurately the activation energy. The acrylo-nitrile-butadiene copolymer showed a decomposition pattern similar to that of polybutadiene. Here, too, the activation energy could not be deduced accurately from the rate curves. Comparative thermal stability in terms of tempe...