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Mechanical stress often accelerates the failure of polymer materials. The aim of this research is to study the interaction between the sealing material FKM and biofuels B10 (heating oil with 10% biodiesel). The mechanical stress test was carried out in a special apparatus. Both mechanical and non-mechanical stress tests were conducted on specimens at 20, 40, and 70 °C for 28 days to document changes in mass, volume, and tensile properties. Both increasing temperature and mechanical stress have a significant effect on the tensile strength of the FKM polymer when exposed to B10. The combination of increasing temperature and mechanical stress induced rupture within 2 h. It was also established that FKM polymer with pre-exposure in B10 survived longer during mechanical stress compared to specimens exposed only to air. With the support of infrared (IR) spectroscopy, we were able to confirm the penetration of B10 into the FKM polymer.
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 fuels and heating oil with admixtures of biogenic sources such as E10 (fuel with 10 % ethanol), E85 (fuel with 85 % ethanol), non-aged and aged biodiesel, diesel fuel with 5 % biodiesel, non-aged and aged B10 (heating oil with 10 % biodiesel) at 20 °C, 40 °C and 70 °C.
Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure for 84 days in the fuels. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens in the biofuels for 42 days.
There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore a threshold of 15 % was determined for the evaluation of the compatibility.
In summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one.
Materials compatibility is a major concern whenever the fuel composition is changed. The question arises of whether sealing materials are resistant to fuels with bioethanol and biodiesel (rapeseed oil fatty acid methyl ester).
Previous research considered 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 fuels and heating oil with admixtures of biogenic substances such as biodiesel and B10 (heating oil with 10 % biodiesel) under purely static conditions.
The aim of this study was to evaluate the fluorocarbon rubber performance under compressed conditions. For the investigations, the mass and the compression set of the FKM test specimens were determined before and after exposure for 3, 7, 14, 28, 56 and 90 days in E10 (fuel with 10 % ethanol), E85 (fuel with 85 % ethanol), biodiesel (fatty acid methyl ester, FAME), Super (fuel with max. 5 % ethanol), diesel fuel with max. 5 % biodiesel, pure diesel fuel, Super Plus (fuel without ethanol) and heating oil with 10 % biodiesel (B10) at 40 °C according to ISO 815-1 “Rubber, vulcanized or thermoplastic - determination of compression set – Part 1: At ambient or elevated temperatures”. The compression set test belongs beside the determination of the Shore hardness, the density and the tensile properties to the basic test methods for elastomers. It was measured in regular time intervals up to a re-drying of more than 90 days after relaxation of test specimens. For comparison, FKM test specimens were exposed without fuel under compressed conditions at 40 °C.
The highest mass increase of FKM test specimens was measured after 90 days exposure in E10 by 9 %, followed by 8 % in Super fuel, by 4 % in E85 and by 0.6 % in biodiesel. Mass increase and swelling of the test specimens in E10 and Super fuel with max. 5 % ethanol had an influence on the compression set values which were subject to high fluctuations in comparison to the values obtained after exposure to other fuels such as biodiesel, diesel fuel and B10.
The results of the present work confirmed the higher swelling of the elastomers such as FKM in E10 obtained under static condition. It can be concluded on the basis of the mass increase and compression set values that FKM is resistant in all fuels under compressed conditions at 40 °C.
The objective of this research was to determine the resistance of frequently used sealing materials such as fluorocarbon rubber (FKM), fluorosilicone rubber (FVMQ), silicone rubber (VMQ), ethylene-propylene-diene rubber (EPDM), chloroprene rub-ber (CR), chlorosulfonated polyethylene (CSM), butyl rubber (IIR), acrylonitrile buta-diene rubber (NBR), polyester urethane rubber (PUR) and polyamide (PA) in non-aged/aged biodiesel and heating oil with 10 % biodiesel at 20 °C, 40 °C and 70 °C. Mass, tensile properties and Shore hardness A/D (for polyamide) of the test speci-mens were determined before and after the exposure for 84/42 days in the aged and non-aged fuels of different age.
Biodiesel fuels are easily oxidized and contain acids and water. The sealing materi-als: acrylonitrile butadiene rubber, butyl rubber, chloroprene rubber, chlorosulfonated polyethylene and ethylene-propylene-diene rubber and were generally not resistant to biodiesel and heating oil with 10 % biodiesel. Fluorocarbon rubber, fluorosilicone rubber and polyamide were the most resistant materials in all tested fuels up to 70 °C. The degree of damage to the sealing materials increased with higher test temperatures and the age of the fuels.
The objective of this research was to determine the resistance of frequently used sealing materials such as EPDM, FKM, FVMQ, CR, CSM, IIR, NBR, PA, PUR and VMQ in aged biodiesel and heating oil B10 with 10 % biodiesel.
The mass, tensile strength, breaking elongation and Shore hardnesses of the test specimens were determined before and after exposure in non-aged, one-year, two-year, three-year and four-year aged biodiesel and B10 at 20 °C, 40 °C and 70 °C.
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. The decrease in tensile properties and Shore hardness increased with the age and the temperature of the biodiesel and the heating oil.
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 and B10. FKM and PA showed high compatibility in non-aged and aged biodiesel. 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 of the age of B10.
The objective of this research was to determine the resistance of frequently used sealing materials such as EPDM, FKM, FVMQ, CR, CSM, IIR, NBR, PA, PUR and VMQ in aged biodiesel and heating oil B10 with 10 % biodiesel.
The mass, tensile strength, breaking elongation and Shore hardnesses of the test specimens were determined before and after exposure in non-aged, one-year, two-year, three-year and four-year aged biodiesel and B10 at 20 °C, 40 °C and 70 °C.
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. The decrease in tensile properties and Shore hardness increased with the age and the temperature of the biodiesel and the heating oil.
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 and B10. FKM and PA showed high compatibility in non-aged and aged biodiesel. 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 of the age of B10.
The objective of this research was to determine the resistance of frequently used sealing materials such as FKM, FVMQ, VMQ, EPDM, CR, CSM, IIR, PA, NBR and PUR in fuels and heating oil with and without admixtures of biogenic sources such as E10, diesel fuel with 5 % biodiesel, non-aged and 2 year aged B10 (heating oil with 10 % biodiesel), pure diesel, standard heating oil and premium grade fuel Super plus at 20 °C, 40 °C and 70 °C.
Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure for 84 days in the fuels. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens in the biofuels for 42 days.
There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore a threshold of 15 % was determined for the evaluation of the compatibility.
In summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one.
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.
Materials compatibility is a major concern whenever the fuel composition is changed in a fuel system. Therefore 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), N8R (acrylonitrile-butadiene rubber) and PUR (polyester urethane rubber) were exposed to E1 0, diese I fuel with 5% biodiesel, non-aged and 2 year aged 810 (heating oil with 10% biodiesel), and for comparison to pure diese! fuel, standard heating oil and Super plus without bioethanol at 20 °C, 40 oc and 70 oc for 84 days. Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens to the biofuels for 42 days.
There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore a threshold of 15% was determined for the evaluation of the compatibility.
The sealing materials FKM, EPDM, N8R, FMVQ, CSM and PA were evaluated on the basis of this threshold as resistant in E1 0 at 20 oc and 40 °C. FKM, FVMQ and PA were resistant at 40 oc , and none of the materials were resistant at 70 °C. FKM and FVMQ absorbed much less 810 and swelled less. CR, CSM, EPDM, IIR, N8R and VMQ were not resistant to 810 at all at 20 oc, 40 oc and 70 oc as the decrease in the tensile properties was significantly over 50%. FVMQ and PA could be evaluated as resistant in non-aged and two year aged 810 at 20 oc and 40 oc, whereas FKM was resistant up to 70 °C. FKM, PA and PUR were evaluated as resistant in standard heating oil and pure diese! fuel at temperatures up to 40°C, only FKM was resistant up to 70°C. FVMQ, FKM, N8R, VMQ, CR and IIR can be evaluated as resistant in premium grade fuel Super plus without ethanol at 20 oc. FKM, FVMQ, VMQ and IIR were still resistant at 40 °C. FKM and FVMQ were evaluated as resistant with restrictions at 70 °C.
ln summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one.
Changes in fuel composition and the introduction of alternative fuels often create problems of degradation in materials. The objective of this research is to study the interaction of the sealing materials FKM, EPDM, CR, CSM, N8R, IIR, VMQ, FVMQ and PA and biofuels such as non-aged and 2 year aged biodiesel (FAME), E1 0 (fuel with 10% ethanol, E85 (fuel with 85% ethanol} and non-aged and 1 year aged 810 (heating oil with 10% biodiesel) in comparison with premium grade fuel without ethanol. Exposure tests were performed with test specimens at 20 °C, 40 oc and 70 oc for 84 days to document the changes in mass, volume and tensile properties. The sealing materials FKM, FVMQ and PA were evaluated as resistant in E10, and FVMQ, VMQ and PA as resistant in E85 at 20 oc and 40 oc. S welling resulted from the high absorption by the elastemers CR, CSM, EPDM, IIR and N8R in comparison to their dissolution in non-aged biodiesei at 40 °C. FKM was still resistant in aged biodiesei at 40 oc but only to a limited degree at 70 °C. The sealing materials CR, CSM, EPDM, IIR and N8R were damaged to a high extent in non-aged and aged 810. Of all the sealing materials, FKM and FVMQ showed high compatibility with these biofuels up to 70 °C.