Spectroscopic and photochemical stability of polystyrene films in the presence of metal complexes

Five metal complexes containing Ni(II), Cu(II), Zn(II), Cd(II) and Sn (II) metals and 4-amino-5-(pyridine-4-yl)-4H-1,2,4-triazole-3-thiol have been prepared for use as polystyrene photostabilizers. The additives (0.5% by weight) were mixed with polystyrene in chloroform to produce modified PS using the casting method. PS films were irradiated (λ = 250-380 nm) with a light absorption intensity of 6.02 × 10−9 ein dm−3 s−1 at room temperature. The photostabilization activity of the films was determined by monitoring various changes, such as the carbonyl index, hydroxyl index, weight loss, viscosity average molecular weight, surface morphology and quantum yield of the chain scission.