Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Degradation of Polyamide-12 pipes aged in fuel
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymera material.
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Polymera material.
(engelsk)Inngår i: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321Artikkel i tidsskrift (Annet vitenskapelig) Submitted
Abstract [en]

In this work properties of polyamide-12 (PA12) fuel lines, exposed for ≤2400 h at 110°C and ≤26000 h at 50°C, containing fuels with different ethanol contents, were investigated. Dynamic mechanical thermal analysis indicated a sizeable loss of plasticiser during ageing. Viscosity measurements suggested that chain scission was an important mechanism of degradation at the higher temperature and size exclusion chromatography suggested that this was probably the case also at 50°C after long ageing times. The molar mass and polydispersity data indicated that the most degraded samples were those exposed to high ethanol contents at 110°C. Thermogravimetry showed that the onset temperature of the main degradation stage was 340-410°C (depending on heating rate). X-ray fluorescence spectroscopy and high performance liquid chromatography indicated migration of stabiliser and in the three-layered pipe, having two PA12 layers divided by a poly(vinylidene fluoride) barrier layer, the migration occurred preferentially from the inner pipe layer into the fuel.

sted, utgiver, år, opplag, sider
Elsevier.
Emneord [en]
Polyamide 12, ageing, fuel lines, ethanol, degradation
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-12035OAI: oai:DiVA.org:kth-12035DiVA, id: diva2:299744
Merknad
QS 20120327Tilgjengelig fra: 2010-02-25 Laget: 2010-02-23 Sist oppdatert: 2017-12-12bibliografisk kontrollert
Inngår i avhandling
1. The Ageing of Fuel Lines Based on Polyamide-12
Åpne denne publikasjonen i ny fane eller vindu >>The Ageing of Fuel Lines Based on Polyamide-12
2010 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Today, the use of bio-fuels for cars is increasing. There is a wide range of biofuelsavailable world wide, in Sweden ethanol containing fuels are favoured.For car manufacturers there is a need to be able to predict short and long termproperties of fuel lines subjected to ethanol containing fuels to ensure properlong term behaviour. The presented method for ageing in “close to real”environment involved circulating fuel inside the tubes and air on the outside attwo temperatures, 50°C and 110°C. The exposure time was extensive in the50°C case, almost 3 years, and the ageing at 110°C was conducted for 100days. Polyamide-12 was chosen as pipe material, which is also used in realparts. Tensile testing was used to assess the mechanical changes caused byageing. Long ageing times and high ethanol levels resulted in low extensibility.In the case of fuel with 25 vol.% ethanol at 110°C (100 days) the samplesshowed no macroscopic yielding. Even at 50°C a time induced loss ofextensibility was observed (80 vol.% ethanol). However, at ethanol levels of 0and 22 vol.% the extensibility was not reduced even after the 3 years of ageing.The changes at short times were interpreted as being due to loss of plasticizer.The changes at long ageing times were thoroughly investigated. The change incrystallinity, pipe swelling, leaching and the decrease in extensibility were allgreatest in the pipes subjected to ethanol. As expected, the molar massdecreased as the ethanol level increased and a good correlation between molarmass and extensibility was observed. A method for determining the fuelpermeation properties was developed. Fuel lines were subjected to circulatingfuels in the same manner as in the ageing tests and the surrounding air wasanalysed for fuel components with a flame ionisation detector. Higher level ofethanol increased the individual fuel component fluxes as well as the total fluxand also the temperature effect on the flux was significant. Finally it should bementioned, that ethanol was not always an unwanted ingredient; adding a smallamount of ethanol to the ethanol-free fuel prevented premature pipe failure at110°C.

sted, utgiver, år, opplag, sider
Stockholm: KTH, 2010. s. 71
Serie
Trita-CHE-Report, ISSN 1654-1081 ; 2010:6
Emneord
pipes, ethanol
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-12050 (URN)978-91-7415-552-5 (ISBN)
Disputas
2010-03-19, F3, KTH, Stockholm, 10:00 (svensk)
Opponent
Veileder
Merknad
QC20100722Tilgjengelig fra: 2010-02-26 Laget: 2010-02-26 Sist oppdatert: 2010-07-22bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Søk i DiVA

Av forfatter/redaktør
Kallio, Kai J.Hedenvist, Mikael
Av organisasjonen
I samme tidsskrift
Polymer degradation and stability

Søk utenfor DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric

urn-nbn
Totalt: 1156 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf