Mechanisms of antioxidant action: autosynergistic antioxidants containing chain-breaking and peroxidolytic functions
✍ Scribed by G. Scott; M.F. Yusoff
- Publisher
- Elsevier Science
- Year
- 1980
- Tongue
- English
- Weight
- 351 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0014-3057
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✦ Synopsis
Antioxidant activities, both in model substrate oxidation and in polypropylene under technological conditions, have been examined for a series of alkyl (3,5-di-tert-butyl-4-hydroxybenzyl) sulphides (I). They were found to be intrinsically much more active than typical commercial chain-breaking antioxidants in a closed system. This higher activity is attributed to an additional antioxidant function resulting from the presence of the sulphur atom. The latter is the precursor for a highly active peroxidolyric species which leads to autosynergism. In a thermal-oxidative (air-oven) test I (R, C2--C~ 8) increases in activity with decreasing volatility but effectiveness as melt stabilizer during the processing of polypropylene and as u.v. stabilizer appears to depend more on the physical state of the additive in the polymer than on its volatility.