The effect of transition metal N,N‐diethyl diselenocarbamates on the photooxidation of polyethylene

The effect of transition metal (Co, Ni, Cr, and Zn) N,N‐diethyl diselenocarbamates over the range of 0.01 to 1.0 part per hundred resin (abbreviated as phr) on the photooxidation of a high density polyethylene film was examined, particularly by changes in the carbonyl IR absorption of the samples. The photooxidation of the polymer was remarkably affected by the kind of metal and concentration of the carbamates, and by the wavelength of irradiated light. Zn and Cr carbamates behaved as oxidation accelerators at lower concentrations over the range of 0.01 to 0.1 phr and as oxidation retarders at concentrations above the range of 0.5 to 1.0 phr. Co and Ni carbamates merely enhanced oxidation and the effect of both these carbamates increased with increasing concentration. Neat polymer gave an emission spectrum at ca. 350 nm which gradually decayed, and a new emission appeared at 470 nm following photooxidation of the samples. The presence of metal carbamates remarkably changed the emission spectra of the polymers, e.g., the disappearance of emission at ca. 350 nm. The roles of these metal carbamates are discussed on the basis of the luminescence and ultraviolet spectral data.