Thermal and Photochemical Processes in Polystyrene in the Glassy State

Abstract

RECENTLY, nylon films irradiated with ultra-violet light¹ have been reported to show a post-effect similar in behaviour to one reported earlier in polystyrene films². It is also suggested that the interpretation advanced for the effect in nylon may be applicable to other polymers. In this note, evidence for different mechanisms in polystyrene is discussed. In nylon, the band that develops during both the irradiation and the post-irradiation periods is centred around 2900 A., while in polystyrene the post-irradiation band is centred around 3400 A. The irradiation spectra for the latter indicate no specific absorption in the region investigated but merely a general increase in absorption. The spectra are shown in Fig. 1, where it is seen that the absorption observed after the post-irradiation period is quite different from that observed immediately after the irradiation period.