Please use this identifier to cite or link to this item: http://repositorio.lnec.pt:8080/jspui/handle/123456789/16873
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dc.contributor.authorReal, L. P.pt_BR
dc.contributor.authorA.M. Ferrariapt_BR
dc.contributor.authorRego, A. M. B.pt_BR
dc.contributor.editorGesellschaft für Umweltsimulation e. V. GUSpt_BR
dc.date.accessioned2009-10-08T11:21:39Zpt_BR
dc.date.accessioned2010-04-27T08:21:08Zpt_BR
dc.date.accessioned2014-10-20T16:44:53Zpt_BR
dc.date.accessioned2017-04-12T14:49:29Z-
dc.date.available2009-10-08T11:21:39Zpt_BR
dc.date.available2010-04-27T08:21:08Zpt_BR
dc.date.available2014-10-20T16:44:53Zpt_BR
dc.date.available2017-04-12T14:49:29Z-
dc.date.issued2009pt_BR
dc.identifier.citation4th EWS, Publication nº 11, 2009, pp 213-222pt_BR
dc.identifier.isbn978-3-9810472-8-8pt_BR
dc.identifier.urihttps://repositorio.lnec.pt/jspui/handle/123456789/16873-
dc.description.abstractIn most of polymer ageing studies conducted at laboratory, there is a trend to underestimate some of the parameters involved in natural exposure, leading to poor simulation results and low reliability of the real world phenomena. Moreover, the nature of polymer and its formulation should be taken into account due to possible synergies and antagonisms between environment and polymer additives. Among the underestimated parameters, we can stress the role of ambient humidity and inorganic fillers. These additives are usually considered to be inert regarding the degradation induced by radiation. In this work, four different PVC formulations, designed for outdoor applications, in the form of calendered films were submitted to artificial accelerated ageing under different radiation sources, without and with spray of water, and to natural exposure. The influence of the different photo-oxidation conditions was evaluated by means of Xray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIRS). The photo-oxidation of PVC can be studied by FTIR measurements following the formation of oxidation products of carbonyl type, due to radical attack to the double bonds in the molecular structure of PVC, enhanced by radiation and temperature. Results have shown that relative rates of PVC degradation reactions are different under different photo-oxidative conditions. XPS results show that, in technical PVC formulations, the fraction of chloride ion trapped in the inorganic filler is a better parameter to measure the PVC degradation (measured by the yellowing index variation) than the amount of total remaining (or lost) chlorine in the surface. When the ageing method includes water jets, the top superficial layer made from the inorganic filler and the organic products from the PVC degradation is removed and leaves behind a much more homogeneous layer which is more resistant towards ageing than the “as processed” one that contains defects introduced by the calendering process. XPS also makes clear that zinc-calcium additive is a better thermal stabilizer than the dibutyltinmaleate and the presence of the tinuvin P retards the PVC degradation. The best simulation of the natural weathering of such PVC materials in laboratory conditions needs to consider, besides the light, the intervention of water jets and/or humidity as well as the existence of light and dark periods.pt_BR
dc.format.extent63562 bytespt_BR
dc.format.mimetypeapplication/pdfpt_BR
dc.language.isoengpt_BR
dc.publisherThomas Reichertpt_BR
dc.rightsopenAccesspt_BR
dc.subjectWeatheringpt_BR
dc.subjectXpspt_BR
dc.subjectFtirpt_BR
dc.subjectPvcpt_BR
dc.subjectYellowingpt_BR
dc.titleAgeing of PVC for outdoor applications: role of water and inorganic fillerspt_BR
dc.typeconferenceObjectpt_BR
dc.identifier.localedicaoPostfach, Pfinztal, Germanypt_BR
dc.description.figures3pt_BR
dc.description.tables1pt_BR
dc.description.pages10 pppt_BR
dc.identifier.seminario4th European Weathering Symposium EWSpt_BR
dc.identifier.localBudapest, Hungriapt_BR
dc.description.sectorDM/NMOpt_BR
dc.name.labelC11pt_BR
dc.description.year2009pt_BR
dc.description.data15 a 18 de Setembropt_BR
Appears in Collections:DM/NMO - Comunicações a congressos e artigos de revista

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