THE DEGRADATION OF POLYSTYRENE: III. THE SCISSION OF POLYSTYLENE BY A VARIETY OF AGENTS AND THE ROLE PLAYED BY THE SOLVENT IN THIS PROCESS
For a number of polystyrenes possessing the Kuhn–Schulz chain length distribution but of different mean chain length, the relation was established between the intrinsic viscosity and the corresponding relative viscosity of a 16% solution in toluene, to facilitate the study of the scission process under conditions similar to those employed by Mesrobian and Tobolsky. It was found that this relation failed to distinguish between those scission points introduced during polymerization and those due to the subsequent degrading action of benzoyl peroxide and air. Assuming polystyrene prepared in a similar manner to that described by Mesrobian and Tobolsky possessed the Kuhn–Schulz chain length distribution it was possible to show that the average number of scission points per structural unit was a linear function of the mass of benzoyl peroxide added to the system and the number of hours exposure to light. The thermal degradation of polystyrene was studied both in the presence and the absence of toluene, and the role of the solvent in the scission of polystyrene by benzoyl peroxide and air was investigated.