Photostabilization of Polystyrene Films

Five transition metal complexes of Ni(II), Cu(II), Zn(II), Cd(II) and Sn(II) with {4-amino-5-(pyridyl)-4H-1,2,4-triazole-3-thiol}, as a ligand (L) has been prepared in alcoholic medium.The photostabilization activity of these compounds was determined by monitoring the carbonyl and hydroxylindexes, weight loss method with irradiation time. It was found that these indexes values increased with irradiation time and this increase depend on the type of additives. The surface morphology for these films was studied during irradiation time. The changes in viscosity average molecular weight of PS with irradiation time were also tracked (using chloroform as a solvent). The quantum yield of the chain scission (¿cs) of these complexes in PS films was also evaluated.