1Construct-Geo,Department of Civil Engineering,Faculty of Engineering,University of Porto,Rua Dr. Roberto Frias,4200-465 Porto,Portugal.
2Requimte,Department of Chemistry and Biochemistry,Faculty of Sciences,University of Porto,Rua do Campo Alegre,687,4169-007 Porto,Portugal.
Microsc Microanal. 2019 Feb;25(1):196-202. doi: 10.1017/S1431927618000430. Epub 2018 Jun 19.
The exposure to solar radiation (mainly due to the action of ultraviolet radiation) is one of the main causes for the premature failure of many polymeric materials, including the geotextiles. In this work, a nonwoven polypropylene geotextile (stabilized with a known amount of a hindered amine light stabilizer) was exposed to ultraviolet-aging tests, both in the laboratory (accelerated conditions) and outdoors (natural conditions). The damage occurred in the geotextile (caused by the ultraviolet-aging tests) was evaluated quantitatively (by monitoring changes in its mass per unit area, thickness, and tensile properties) and qualitatively (by scanning electron microscopy). The results, among other findings, showed that: (1) the ultraviolet-aging tests (both in the laboratory and outdoors) induced relevant damage in the polypropylene fibers of the geotextile (transverse cracks), leading to the deterioration of its tensile behavior, (2) the amount of degradation increased with the increase of the ultraviolet radiant energy, (3) the laboratory tests caused a faster deterioration of the polypropylene fibers than the outdoor tests, and (4) the degradation found by scanning electron microscopy in the polypropylene fibers correlated well with the deterioration occurred in the tensile behavior of the geotextile.
暴露在太阳辐射下(主要是由于紫外线辐射的作用)是许多聚合材料(包括土工织物)过早失效的主要原因之一。在这项工作中,一种无纺聚丙烯土工织物(用已知量的受阻胺光稳定剂稳定)进行了紫外线老化试验,包括实验室(加速条件)和户外(自然条件)。通过监测单位面积质量、厚度和拉伸性能的变化,对土工织物中的损伤(由紫外线老化试验引起)进行了定量(quantitatively)和定性(qualitatively)评估。结果表明:(1)紫外线老化试验(无论是在实验室还是户外)都会在土工织物的聚丙烯纤维中引起明显的损伤(横向裂缝),导致其拉伸性能恶化;(2)降解程度随紫外线辐射能的增加而增加;(3)实验室试验比户外试验导致聚丙烯纤维更快的劣化;(4)扫描电子显微镜在聚丙烯纤维中发现的降解与土工织物拉伸性能的劣化密切相关。