TY - CONF A1 - Weltschev, Margit A1 - Heming, Frank A1 - Haufe, Manuela A1 - Heyer, Martina T1 - The influence of the age of biodiesel and B10 on the resistance of sealing materials at different temperatures N2 - Materials compatibility is a major concern whenever the fuel composition is changed in a fuel system. The question arises of whether sealing materials are resistant to fuels with bioethanol and biodiesel (rapeseed oil fatty acid methyl ester). The objective of this research was to determine the resistance of frequently used sealing materials such as FKM (fluorocarbon rubber), FVMQ (methyl-fluoro-silicone rubber), VMQ (methyl-vinyl-silicone rubber), EPDM (ethylene-propylene-diene rubber), CR (chloroprene rubber), CSM (chlorosulfonated polyethylene), IIR (butyl rubber), PA (polyamides), NBR (acrylonitrile-butadiene rubber) and PUR (polyester urethane rubber) in aged fuels and heating oil with admixtures of biogenic substances such as biodiesel and B10 (heating oil with 10% biodiesel). The mass, tensile strength and breaking elongation of the test specimens were determined before and after exposure for 84 days in non-aged, one-year, two-year, three-year and four-year aged biodiesel and B10 according to DIN 53504 – “Testing of rubber - determination of tensile strength at break, tensile stress at yield, elongation at break and stress values in a tensile test”. The visual examination of some elastomer test specimens clearly showed the great volume increase until breaking or partial dissolution. The Shore hardnesses A and D (for PA) were determined before and after exposure of the test specimens in the biofuels for 42 days according to DIN 53505 – “Testing of rubber – Shore A and Shore D hardness test”. A threshold for the reduction in tensile properties and Shore hardness is not set in the international standards. Therefore, a threshold of 15 % was set for the evaluation of the compatibility. Biodiesel fuels are easily oxidized and contain acids and water. The age of the biodiesel was not relevant for the sealing materials CR, CSM, EPDM, IIR and NBR, which were generally not resistant to biodiesel. FKM and PA showed high compatibility in non-aged, one-year, two-year, three-year and four- year aged biodiesel, which was attributed to the absence of polarity. The decrease in tensile properties and Shore hardness increased with the age and the temperature of the biodiesel, but the measured values were still lower than the defined threshold. FKM and FVMQ absorbed much less non-aged and aged B10 and swelled less. CR, CSM, EPDM, IIR, NBR and VMQ were not resistant to B10 at all at 20°C, 40°C and 70°C as the decrease in the tensile properties was significantly over 50%. FVMQ and PA could be evaluated as resistant in non-aged and aged B10 at 20°C and 40°C, whereas FKM was resistant up to 70°C despite the age of the B10. The damaging impact of B10 increased with the age and the temperature. T2 - EUROCORR 2016 CY - Montpellier, France DA - 11.09.2016 KW - Sealing materials KW - Compatibility evaluation KW - Biofuels KW - Tensile properties KW - Shore hardness PY - 2016 AN - OPUS4-37430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -