Wu Q, Qu BJ, Wu QH (2001) Surface photo-oxidation and photostabilization in photoinitiated crosslinking of polyethylene. Chemical Journal of Chinese Universities-Chinese 22(9), 1610-1613. [In Chinese]

Web link: Keywords:

photocross-linked polyethylene; surface photo-oxidation; photostabilization; pre-irradiation; hindered amine light stabilizers; (HALS); low-density polyethylene; linked polyethylene; cross-linking;

Abstract: The surface photo-oxidation and photostabilization in the photoinitiated crosslinking of polyethylene were studied using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and the determination of gel content with irradiation time. The data show that the surface photo-oxidation of photocrosslinked polyethylene (XLPE) increases apparently with increasing UV-irradiation time. The main photo-oxidation products have been identified as hydroperoxides and various carbonyl compounds. The photostabilization of XLPE can be realized by suitable pre-irradiation using low-pressure mercury(LPM) lamp or by the addition of some hindered amine light stabilizers (HALS). The optimum time of pre-irradiation by LPM lamp is 10 s under the experimental conditions in the present study. However, some HALS can reduce the efficiency of photoinitiated crosslinking process of PE.