Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Effects of ageing conditions on degradation of acrylonitrile butadiene rubber filled with heat-treated ZnO star-shaped particles in rapeseed biodiesel
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.ORCID-id: 0000-0002-7348-0004
KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.ORCID-id: 0000-0001-5867-0531
Visa övriga samt affilieringar
2017 (Engelska)Ingår i: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The degradation of acrylonitrile butadiene rubber (NBR) after exposure to biodiesel at different oxygen partial pressures in an automated ageing equipment at 80 °C, and in a high-pressure autoclave at 150 °C was studied. The oxidation of biodiesel was promoted by an increase in oxygen concentration, resulting in a larger uptake of fuel in the rubber due to internal cavitation, a greater decrease in the strain-at-break of NBR due to the coalescence of cavity, and a faster increase in the crosslinking density and carbonyl index due to the promotion of the oxidation of NBR. During the high-temperature autoclave ageing, less fuel was absorbed in the rubber, because the formation of hydroperoxides and acids was impeded. The extensibility of NBR aged in the autoclave decreased only slightly due to the cleavage of rubber chains by the biodiesel attack. The degradation of NBR in the absence of carbon black was explained as being due to oxidative crosslinking. The dissolution of ZnO crystals in the acidic components of biodiesel was retarded by removing the inter-particle porosity and surface defects through heat treating star-shaped ZnO particles. The rubber containing heat-treated ZnO particles swelled less in biodiesel than a NBR filled with commercial ZnO nanoparticles, and showed a smaller decrease in the strain-at-break and less oxidative crosslinking.

Ort, förlag, år, upplaga, sidor
Elsevier, 2017.
Nyckelord [en]
Acrylonitrile butadiene rubber; Biodiesel; Degradation; Oxidation; Heat treatment; Zinc oxide
Nationell ämneskategori
Polymerteknologi
Identifikatorer
URN: urn:nbn:se:kth:diva-202418DOI: 10.1016/j.polymdegradstab.2017.02.011ISI: 000400222500004Scopus ID: 2-s2.0-85014171938OAI: oai:DiVA.org:kth-202418DiVA, id: diva2:1076847
Anmärkning

QC 20170228

Tillgänglig från: 2017-02-24 Skapad: 2017-02-24 Senast uppdaterad: 2017-05-23
Ingår i avhandling
1. Degradation of acrylonitrile butadiene rubber and fluoroelastomers in rapeseed biodiesel and hydrogenated vegetable oil
Öppna denna publikation i ny flik eller fönster >>Degradation of acrylonitrile butadiene rubber and fluoroelastomers in rapeseed biodiesel and hydrogenated vegetable oil
2017 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Biodiesel and hydrotreated vegetable oil (HVO) are currently viewed by the transportation sector as the most viable alternative fuels to replace petroleum-based fuels. The use of biodiesel has, however, been limited by the deteriorative effect of biodiesel on rubber parts in automobile fuel systems. This work therefore aimed at investigating the degradation of acrylonitrile butadiene rubber (NBR) and fluoroelastomers (FKM) on exposure to biodiesel and HVO at different temperatures and oxygen concentrations in an automated ageing equipment and a high-pressure autoclave. The oxidation of biodiesel at 80 °C was promoted by an increase in the oxygen partial pressure, resulting in the formation of larger amounts of hydroperoxides and acids in the fuel. The fatty acid methyl esters of the biodiesel oxidized less at 150 °C on autoclave aging, because the termination reactions between alkyl and alkylperoxyl radicals dominated over the initiation reactions. HVO consists of saturated hydrocarbons, and remained intact during the exposure. The NBR absorbed a large amount of biodiesel due to fuel-driven internal cavitation in the rubber, and the uptake increased with increasing oxygen partial pressure due to the increase in concentration of oxidation products of the biodiesel. The absence of a tan δ peak (dynamical mechanical measurements) of the bound rubber and the appearance of carbon black particles devoid of rubber suggested that the cavitation was caused by the detachment of bound rubber from particle surfaces. A significant decrease in the strain-at-break and in the Payne-effect amplitude of NBR exposed to biodiesel was explained as being due to the damage caused by biodiesel to the rubber-carbon-black network. During the high-temperature autoclave ageing, the NBR swelled less in biodiesel, and showed a small decrease in the strain-at-break due to the cleavage of rubber chains. The degradation of NBR in the absence of carbon black was due only to biodiesel-promoted oxidative crosslinking. The zinc cations released by the dissolution of zinc oxide particles in biodiesel promoted reduction reactions in the acrylonitrile part of the NBR. Heat-treated star-shaped ZnO particles dissolved more slowly in biodiesel than the commercial ZnO nanoparticles due to the elimination of inter-particle porosity by heat treatment. The fuel sorption was hindered in HVO-exposed NBR by the steric constraints of the bulky HVO molecules. The extensibility of NBR decreased only slightly after exposure to HVO, due to the migration of plasticizer from the rubber. The bisphenol-cured FKM co- and terpolymer swelled more than the peroxide-cured GFLT-type FKM in biodiesel due to the chain cleavage caused by the attack of biodiesel on the double bonds formed during the bisphenol curing. The FKM rubbers absorbed biodiesel faster, and to a greater extent, with increasing oxygen concentration. It is suggested that the extensive biodiesel uptake and the decrease in the strain-at-break and Young’s modulus of the FKM terpolymer was due to dehydrofluorination of the rubber by the coordination complexes of biodiesel and magnesium oxide and calcium hydroxide particles. An increase in the CH2-concentration of the extracted FKM rubbers suggested that biodiesel was grafted onto the FKM at the unsaturated sites resulting from dehydrofluorination.

Ort, förlag, år, upplaga, sidor
Stockholm, Sweden: KTH Royal Institute of Technology, 2017. s. 63
Serie
TRITA-CHE-Report, ISSN 1654-1081 ; 2017:9
Nyckelord
Degradation; Acrylonitrile butadiene rubber; Fluoroelastomers; Biodiesel; Hydrotreated vegetable oil; Cavitation; Bound rubber; Dehydrofluorination.
Nationell ämneskategori
Polymerteknologi
Forskningsämne
Fiber- och polymervetenskap
Identifikatorer
urn:nbn:se:kth:diva-202422 (URN)978-91-7729-274-6 (ISBN)
Disputation
2017-03-31, F3, 10:00 (Engelska)
Opponent
Handledare
Anmärkning

QC 20170227

Tillgänglig från: 2017-02-27 Skapad: 2017-02-24 Senast uppdaterad: 2017-06-26Bibliografiskt granskad

Open Access i DiVA

fulltext(35821 kB)166 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 35821 kBChecksumma SHA-512
ff09b22e80acf432895202049a7d2cbf02d19a574651404f74c86c11de340118de2e7cb4c2f39e33e16c6cf005612858c48f15d5a7e02d4bcfc7dd79a0850907
Typ fulltextMimetyp application/pdf

Övriga länkar

Förlagets fulltextScopus

Personposter BETA

Pourrahimi, A. M.

Sök vidare i DiVA

Av författaren/redaktören
Akhlaghi, ShahinPourrahimi, A. M.Mikael S., HedenqvistUlf W., Gedde
Av organisationen
Fiber- och polymerteknologi
I samma tidskrift
Polymer degradation and stability
Polymerteknologi

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 166 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 1532 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf