کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5204688 | 1381968 | 2008 | 8 صفحه PDF | دانلود رایگان |
We have determined the activation energies (Ea) of yellowing and gloss loss for a large number of engineering thermoplastics and blends under accelerated weathering conditions. The Ea often depend on the property measured and exposure conditions, although they vary over a fairly small range. Under the CIRA/sodalime-filtered xenon arc conditions most likely to be representative of outdoor exposure, the Ea for gloss loss was â¤5 kcal/mol for all samples tested. The Ea for yellowing was also â¤5 kcal/mol except for SAN and ABS. Evidently the color bodies formed from photo-oxidation of SAN are more sensitive to temperature. A reaction with an Ea of 5 kcal/mol will increase its rate by about 33% for each 10 °C increase in temperature near room temperature. Temperature is an important, but not overwhelming, variable in the weathering of most engineering thermoplastics.
Journal: Polymer Degradation and Stability - Volume 93, Issue 3, March 2008, Pages 684-691