Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5203471 | Polymer Degradation and Stability | 2008 | 9 Pages |
Abstract
The chemical and physical properties of polyamide-12 (PA12) fuel pipes/lines, aged for â¤2400 h at 110 °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 °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.
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
K.J. Kallio, M.S. Hedenqvist,