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- Beitrag zu einem Tagungsband (7) (entfernen)
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- Compatibility (5)
- Biofuels (4)
- Polyethylene grades (3)
- Sealing materials (3)
- Tensile properties (3)
- B10 (2)
- Biodiesel (2)
- Change in MFR and tensile properties (2)
- E85 (2)
- Aged biodiesel (1)
Organisationseinheit der BAM
Resistance to oxidative degradation by nitric acid has been selected for a comparison of polyethylene grades in a European standard on suitability proof for alternative plastic resins used for packagings and intermediate bulk containers (IBCs) for the transport of dangerous goods. Measurements of the infrared (IR) absorption spectra of microtome slices cut from the walls of jerricans, which were pre-stored with 55% nitric acid for 21 and 42 days at 40°C, showed changes in the structure of the polyethylene. The penetration depths of 55% nitric acid into the polyethylene grades are, in principle, suitable for evaluating the resistance to oxidative degradation of polyethylene grades after pre-storage of the packagings for 21 days. After this period the packaging wall is not fully penetrated. The intensities of the IR bands at 1565 cm-1 (-NO2), 1630 cm-1 (-C=C) and 1654 cm-1 (-O-NO2) increased with the treatment time with 55% nitric acid as a result of oxidative damage by the nitric acid. The high increase in absorbance of the -C=C band in the region 1630 - 1690 cm-1 is attributable to paraffinic chain cracks. The absorbance of the -O-NO2 band, formed as result of the nitration process was still low at a test temperature of 40°C.
Biofuels including ethanol and biodiesel (fatty acid methyl ester) represent an impor-tant renewable fuel alternative to petroleum-derived transport fuels. Increasing bio-fuel use would bring some benefits, such as a reduction in oil demands and green-house gas emissions, and an improvement in air quality.
Materials compatibility is a major concern whenever the fuel composition is changed in a fuel system.
The aim of this work is to study the interaction between sealing materials such as FKM (fluorocarbon rubber), EPDM (ethylene-propylene-diene rubber), CR (chloro-prene rubber), CSM (chlorosulfonated polyethylene), NBR (acrylonitrile-butadiene rubber), IIR (butyl rubber), VMQ (methyl-vinyl-silicone rubber) and FVMQ (methyl-fluoro-silicone rubber) and biofuels such as biodiesel, E85 (fuel with 85% ethanol) and B10 (heating oil with 10% biodiesel) at 70°C for 84 days. Experiments were con-ducted with tests specimens of theses elastomers to document the changes in the mass and tensile properties of these sealing materials according to ISO 1817.
The exposure tests of the elastomers in E85 at 70°C showed that the weight gain caused by swelling of the test specimens was in the range of 3% to 12%. However, the weight gain of the fluorinated elastomers was at the lower end of this range. Tensile strength and breaking elongation decreased by 22% to 61% or 13% to 77%. The lowest decrease in the tensile properties was determined for FKM, EPDM und IIR. These sealing materials were evaluated as resistant to E85 up to a temperature of 70°C.
Biodiesel absorbed water more quickly and aged faster than conventional diesel fuel. The weight loss of the elastomers varied between 9% (FKM) and 126% (CSM) in biodiesel. FKM was evaluated as resistant with a 16% reduction in tensile strength, a 2% reduction in breaking elongation and low weight loss. NBR, EPDM, CSM and VMQ were evaluated as not resistant. CSM even lost 84% of its original tensile strength and 78% of its breaking elongation.
The highest weight gain as a result of swelling was measured for CSM with 86%, for EPDM with 84% and for VMQ with 54% in B10, while the fluorine-containing elasto-mers FKM (1%) and FVMQ (3%) absorbed much less B10 and swelled less. FKM lost 23% in tensile strength and 17% in breaking elongation; FMVQ lost 29% in ten-sile strength and 36% in breaking elongation. FMVQ was, therefore, only limited in its resistance to B10.
The elastomers NBR, EPDM, CSM and VMQ were not resistant to B10 at all as the decrease in the tensile properties was significantly over 50%. NBR lost about 93% and CSM about 100% of its breaking elongation.
The conclusion of the investigations at 70°C is that FKM is the most resistant sealing material in biodiesel, E85 (fuel with 85% ethanol) and B10 (heating oil with 10% biodiesel).
8iofuels including ethanol and biodiesel (fatty acid methyl ester) represent an important renewable fuel alternative to petroleum-derived transport fuels. lncreasing biofuels use would bring some benefits, such as a reduction in oil demands and greenhause gas emissions, and an improvement in air quality.
Biofuels including ethanol and biodiesel (FAME) represent a renewable fuel alternative to petroleum-derived transport fuels. The aim of this work was to study the interaction between high density polyethylene (HDPE) with permeation barriers in form of polyamide (PA) and fluorination, and biofuels such as E85 (fuel with 85 % ethanol), biodiesel and B10 (heating oil with 10 % biodiesel). 10 l jerrycans made of polyethylene with permeation barrier of PA were filled with E85 and biodiesel and exposed to temperatures of 20 °C and 40 °C for 5 years. Half of the 20 l jerrycans of HDPE for filling with B10 were fluorinated at the inner layer to prevent permeation before the exposure. Tensile properties were determined once a year, and FTIR-spectroscopy was used to evaluate possible changes.
The tensile properties tensile strength and breaking elongation of HDPE jerrycan cuttings with permeation barrier decreased, but not significantly, after immersion in E85, biodiesel and B10. The elasticity modulus of the polyethylene grades was especially reduced during exposure to E85.
The FTIR spectra of HDPE jerrycan cuttings with permeation barrier showed that immersion tests for five years with the test fuels at 20 °C and 40 °C did not lead to a decomposition of the permeation barriers.
The aim of this work was to study the interaction between high density polyethylene (HDPE) grades as material for dangeraus goods packagings and biofuels such as E10 (fuel with 10% ethanol), E85 (fuel with 85% ethanol), biodiesei and 810 (heating oil with 10% biodiesel). Jerricans made of two polyethylene grades were filled with these fuels and exposed to temperatures of 20 oc and 40 oc for more than one year. Tensile properlies (tensile strength, breaking elongation and elasticity modulus) and Melt Flow Rate (MFR) were determined, and Fourier Transform Infrared Spectroscopy (FTIR) was used to evaluate changes in the chemical structure.
Measurements of the MFR and tensile properlies of the polyethylene grades after exposure to E1 0, E85 and 810 showed only a slightly damaging influence. A n increase in the peak of 1585 cm·1 for the (C=C) stretching vibrations was visible in the FTIR spectra after immersion tests with E85. A n increase in the MFR with the immersion time of the grades in biodiesei was measured - in parlicular, after one year of exposure. The elasticity modulus of the polyethylene grades was reduced with the immersion time too. The FTIR spectra showed a broadening of the C=O peak of 1740 cm·1 and the appearance of the hydroxyl group at 3500 cm·1.
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.
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.