Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5203423 | Polymer Degradation and Stability | 2011 | 10 Pages |
Abstract
Plastic pipes are often exposed to a range of environmental conditions which may lead to their degradation. The most important influence factors are UV radiation, humidity and temperature. These can cause leaching of long-term and light stabilisers and finally oxidation of the polymer. In this study we demonstrate how the elemental steps of the photooxidative degradation of polyethylene pipes can be monitored by IR-microscopy. In detail the influence of UV radiation leads to a depletion of the phenolic long-term stabiliser, Irganox 1010. Calibration of the spectroscopic data enables IR-microscopy to be carried out in a quantitative manner and the rate constants for the stabiliser loss to be calculated for the first time. The results obtained from IR-microscopy are well in agreement with those obtained by mechanical sample preparation and measurement of the oxidative induction time (OIT) as well as extraction coupled with chromatographic analysis (HPLC). A mechanism based on Norrish type cleavage is proposed. Also the formation of trans-vinylidene groups as unsaturated degradation products of the PE can be observed. In summary it can be shown that IR-microscopy is highly superior to the conventional approach of mechanical sample preparation with regard to spatial resolution and offers the advantage of being less labour intensive.
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Raquel Maria, Karsten Rode, Robert Brüll, Frank Dorbath, Benjamin Baudrit, Martin Bastian, Emmanuelle Brendlé,