Ageing properties of polyamide-12 pipes exposed to fuels with and without ethanol
2008 (English)In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 93, no 10, 1846-1854 p.Article in journal (Refereed) Published
The chemical and physical properties of polyamide-12 (PA12) fuel pipes/lines, aged for <= 2400 h at 110 degrees C, have been investigated. The pipes, containing fuel with or without ethanol, were either of a single PA12 layer, or of two PA12 layers surrounding a poly(vinylidene fluoride) barrier layer. The molar mass of the inner surface region obtained by size-exclusion chromatography was reduced during ageing. and optical microscopy revealed a surface that was partly dissolved in the presence of ethanol. Infrared spectroscopy revealed a rapid loss of plasticiser, especially in the presence of ethanol, and the fuel contained plasticiser and other polymer related components. Immersion tests at 60 degrees C showed that the swelling of the pipe and the amount of dissolved material were greatest for the fuels with intermediate ethanol content (50 vol.%). Aged samples experienced an increase in melting point, presumably, to a large extent, due to the loss of plasticiser and/or PA12-related components. In addition, for several samples, the crystallinity seemed to increase with ageing. (C) 2008 Elsevier Ltd. All rights reserved.
Place, publisher, year, edition, pages
2008. Vol. 93, no 10, 1846-1854 p.
Polyamide-12, Ageing, Fuel lines, Pipes, Ethanol, Swelling, THERMAL-DECOMPOSITION, ALIPHATIC POLYAMIDES, CHROMATOGRAPHY, DEGRADATION, KINETICS
IdentifiersURN: urn:nbn:se:kth:diva-12043DOI: 10.1016/j.polymdegradstab.2008.07.025ISI: 000260648800019ScopusID: 2-s2.0-52049113185OAI: oai:DiVA.org:kth-12043DiVA: diva2:300206