Ageing of low-temperature coal-tar pitch. 1. Influence of weather and u.v. light

✍ Scribed by Jürg E. Rüede

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 377 KB
• Volume: 58
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(79)90009-7

✦ Synopsis

Outdoor weathering or exposure to U.V. light causes chemical changes on the surface of pitch which can be studied with infrared spectroscopy. Several changes -increase of oxygen content and aromaticity -take place at the same time but at different rates. Carbonyl groups are formed considerably faster than phenols or aromatics. The changing properties are hyperbolic function of time and approach a definite limit.