Thermal degradation of polystyrene in different environments

Several aspects of the thermal degradation of polystyrene are highlighted in this communication. The factors involved in determining the ratio of volatile to tar fraction products in the degradation of the pure polymer are examined, leading to the conclusion that the initial melt viscosity plays an important role in determining the balance between intra‐ and intermolecular transfer. The effect on the degradation of polystyrene of the presence of a second polymer is discussed. For polystyrene‐polybutadiene and polystyrene‐polyisoprene blends, stabilisation is observed, which is attributed to radical scavenging. The thermal degradation behaviour of polystyrene in the presence of oxygen has been investigated, with and without an antioxidant additive. Products have been characterised for oxidative conditions and the kinetics of degradation have been studied.