The action of a benzotriazole light stabilizer in wool. II. The mechanism of photostabilization

✍ Scribed by Leaver, Ian H.

• Book ID: 105334004
• Publisher: John Wiley and Sons
• Year: 1982
• Weight: 925 KB
• Volume: 20
• Category: Article
• ISSN: 0360-6376
• DOI: 10.1002/pol.1982.170200907

✦ Synopsis

Abstract

A study was made of the photoprotective effect of a sulfonated hydroxyphenylbenzotriazole light stabilizer in wool fabric. Investigations of the absorption, luminescence quenching, and photostabilizing properties of the benzotriazole showed that optical screening is the key mode of operation. Excited‐state quenching is of little practical importance. The protective effect of the stabilizer is strongly dependent on the exposure conditions. There is a good correlation between UV screening ability and photoprotection at wavelengths near 300 nm where the fiber has maximum photosensitivity but the correlation in the spectral region of 314–390 nm is poor. The failure of the benzotriazole to provide good protection in the near‐UV region of the spectrum is attributed mainly to the sensitizing action of a small number of fluorescent molecules of the stabilizer, the internal hydrogen bond of which has been disrupted by the influence of the polar environment of the substrate.