Tailored ageing tests of transparent roof panels.
Ulrich Schulz, Berlin, und Grace Tschandramadjas, Highett/ Australien
ABSTRACT In order to predict the lifetime expectance of transparent polymers for roof panels specific artificial weathering procedures of accaptable duration are presented. They simulate the Worst Case weathering scenario, a cyclic combination of ultraviolet radiation, temperature and moisture causing the same type of degradation as occurring under natural weathering. In outdoor applications ageing leads to the gradual loss of material transparency and appearance during service life which is desired to span at least 50 years. Spectral opacity, craze development, acid sensitivity and brittleness of polymethylmetacrylate (PMMA) and polycarbonate (PC) are determined under UV exposure, different relative humidity and surface wetness: dry, 98% humidity and wet. The two polymers that undergo photochemical ageing require very different treatment for accelerated testing. The investigations suggest that current standard methods by artificial weathering are not generally appropriate to the specific Worst Case Scenario of different materials.
Publication Source: Materialprüfung, ISSN: 0025-5300
Issue: 2003-11/12, pp -
Publisher: Carl Hanser Verlag München
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