Study of degradation of polystyrene, using ultraviolet spectrophotometry

Abstract

The role of ultraviolet radiant energy and effect of presence of monomer on degradation of polystyrene were st udied by means of ultaviolet absorption techniques. It was found that ~xposure of pure pol,Ystyrene to ultravio~e t .radiant energy resulted in increased absorption III th~ ultravIOlet regIOn of 280 to 400 millimicrons, whICh advanced progressively as exposure t une lllcreased. The presence of monomer increased the rate of d egradation without altering the general type of abso~p.tion. A post-radiation effe~t was noted in both the pUlified polymer and polymer contallllllg monomer styrene. Agam, t he presence of monomer increased the ra~e of progress of the post-radiation effect. Possible mechanisms are postulated for t he ultravIOlet degradatIOn, and the concept of e ntrapped free radicals is considered as a possible explanation for the post-radiation effect observed.