Reducing the hydrocarbon gas diffusion and increasing the pressure-impact strength of fuel transfer pipelines for use in the automotive industry using radiation crosslinked polyamide 12

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Hıdıroglu M., Aksüt D., Serce O., Karabulut H., Şen M.

RADIATION PHYSICS AND CHEMISTRY, vol.159, pp.118-123, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 159
  • Publication Date: 2019
  • Doi Number: 10.1016/j.radphyschem.2019.02.039
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.118-123
  • Keywords: Irradiated polyamides, Carbon emissions, Mechanical properties of polyamides, DYNAMIC-MECHANICAL PROPERTIES, ELECTRON-BEAM IRRADIATION, CHAIN SCISSION, LINKING, NYLON-66
  • Hacettepe University Affiliated: Yes


The main aim of this study was to reduce the rate of daily hydrocarbons (HC) released into the atmosphere from polyamide-based automotive fuel transfer system pipes due to diffusion using radiation processing technology. The second aim of this study was to improve the pressure level and impact strength of these pipelines. In order to manage these aims, layer by layer extruded pipelines constructed from different types of thermoplastic materials (i.e. PA6, EVOH and radiation crosslinkable 5% 1,3,5-triallyl-1,3,5-triazin-2,4,6(1H,3H,5H)-trion (TALC) containing PA12 (Creamid-12)) were irradiated using gamma-rays (up to 100 kGy) at room temperature to carry out a radiation-induced crosslinking process. The mechanical properties of the samples were evaluated using tensile and cold impact tests. Sol-gel analysis of the irradiated samples was performed to determine the gel content, gelation dose and chain scission/crosslinking ratio. The Charlesby-Pinner and Charlesby-Rosiak equations were used for our calculations. The change in the HC diffusion of the crosslinked pipes was measured using a sealed housing for evaporative determination (SHED) device. An improvement in the pressure resistance was observed for the samples under an increasing fluid pressure using a blasting test device. The SHED results showed that the gas permeability value is reduced similar to 1.9 fold in the 65 kGy irradiated fuel transfer pipelines. The blasting test results indicate that the average pressure resistivity of the 65 kGy irradiated and 76.5% cross-linked pipe samples was similar to 19% greater than that observed for the unirradiated samples. The results of this study show that the radiation cross-linking process is an excellent strategy to reduce the daily hydrocarbon emissions from new generation fuel transfer pipelines.