Evidence for the reduction of quinones added during thermal processing of polypropylene and the resultant effect on polymer light stability
✍ Scribed by N. S. Allen; J. F. McKellar; S. A. Protopapas
- Publisher
- John Wiley and Sons
- Year
- 1978
- Tongue
- English
- Weight
- 307 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The thermal and photochemical oxidation of anthraquinone‐ and p‐benzoquinone‐doped polypropylene has been studied by absorption, luminescence, and infrared spectroscopy. Prior to irradiation, fluorescence and phosphorescence measurements showed that some of the anthraquinone and most of the p‐benzoquinone had been converted into their corresponding hydroquinones during processing. The p‐benzoquinone, unlike anthraquinone, also imparted a blue coloration to the polymer before irradiation, which is associated with the formation of a quinhydrone complex (or complexes). These results indicate that the quinones are thermally reduced to their corresponding hydroquinones during processing by a mechanism of hydrogen atom abstraction from the polymer substrate. On photo‐oxidation, whereas anthraquinone acted as a photosensitizer, p‐benzoquinone acted as a photostabilizer.