Estimation of resistance of engine rubber sealants to influence of mixed diesel fuel (original) (raw)
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Deterioration of automotive rubbers in liquid biofuels: A review
Renewable and Sustainable Energy Reviews, 2015
Concerns over the fast depletion of fossil fuels, environmental issues and stringent legislation associated with petroleum-based fuels have triggered a shift to bio-based fuels, as an alternative to meet the growing energy demand in the transportation sector. However, since conventional automobile fuel systems are adapted to petroleum-based fuels, switching to biofuels causes a severe deterioration in the performance of currently used rubber components. The degradation of the rubber materials in biofuels is complicated by the presence of different additives in biofuels and rubber compounds, by oxidation of biofuels and by the effects of thermomechanical loadings in the engine. This paper presents a comprehensive review of the effects of different types of biofuels, particularly biodiesel and bioethanol, on the physical, mechanical, morphological and thermal properties of elastomers under different exposure conditions. In addition, the literature data available on the variation of rubbers' resistance to biofuels with the changes in their monomer type and composition, cure system and additives content was also studied. The review essentially focuses on the compatibility of biofuels with acrylonitrile butadiene rubber, fluoroelastomers, polychloroprene rubber and silicon rubber, as the most commonly used automotive rubbers coming into contact with fuels during their service. The knowledge summarized in this study can help to develop a guideline on the selection of rubber for automotive parts designed to withstand biofuels.
Influence of Synthetic Fuel on Nitrile Rubbers Used in Aviation
Transport Problems
This paper investigates the influence of alternative fuel on selected butadiene-acrylonitrile rubbers used as seals in engine and fuel supply systems of post-Soviet aircrafts. The conventional fuel Jet A-1, the synthetic blending component from hydrotreated esters and fatty acids (HEFA) and its blend were interacted with the sample nitrile rubbers. HEFA technology has been approved by ASTM D7655 for use in turbine aircraft engines. The effect was evaluated on the basis of changes in the nitrile rubber's volume, mass and hardness. It has been confirmed that the synthetic component containing no aromatic hydrocarbons has a different effect on nitrile rubber than the conventional fuel. When the nitrile rubbers were subjected to microscopic observations, the most frequently observed effect was washing out or dissolving of nitrile rubber surface fragments.
Chemical degradation of nitrile rubber in biodiesel
Nitrile rubber is a typical material used in automotive systems, e.g. gaskets, seals and fuel hoses that remain in constant contact with the fuel. Its compatibility with fossil fuels has been assessed and proven, but its compatibility with biodiesel was investigated and reported herein. Biodiesel is an alternative and eco-friendly biofuel that substitutes diesel and is obtained from renewable resources such as vegetable oils and animal fats. Its properties are similar to those of diesel, but it is more hygroscopic and prone to be oxidized, characteristics that increase its corrosive and degradation effects on elastomers. Hence, the main objective of this work was to assess the effect of different diesel-biodiesel blends on the resistance of nitrile rubber at different temperatures and operation conditions. The methodology applied consisted of gravimetric tests, tensile strength measurements, FTIR analysis, acid number measurement as an indicator of fuel degradation, scanning electro...
Reactive and Functional Polymers, 2004
Thermogravimetric analysis (TGA), flammability and oil resistance in natural rubber (NR) and dichlorocarbene modified styrene butadiene rubber (DCSBR) blends were investigated as a function of different composition. TGA plot confirms the better thermal stability and flame resistance of DCSBR as well as its blends with NR. The simultaneous difference temperature plot showed the energy requirement for the degradation pattern of the blends. The flammability of the blend was monitored by the limiting oxygen index (LOI) measurement of the rubber vulcanizate. The amount of DCSBR in the blend significantly affected the properties of blends. The mechanical properties investigated after the immersion in ASTM oil was tensile strength, modulus, tear strength and hardness. It was found that these properties were decreases progressively with increasing NR content in the blends.
Effect of Rubber Blend Compositions on Their Mechanical and Oil Resistance Characteristics
The International Conference on Chemical and Environmental Engineering (Print), 2008
Polymer blends represent a field of intensive research. In the present work, different rubber blends based on nitrile butadiene rubber, NBR (N3980-39% acrylonitrile) have been selected to get a product with high oil resistance and good mechanical properties. The ratio of each component (NBR and chloroprene rubber CR) in NBR-CR blends has been varied and the corresponding vulcanizing systems have been carefully selected. The rheological properties of the different blends obtained were evaluated. For instance, the scorch time, optimum time of vulcanization have been determined and correlated with the blends composition. The mechanical properties, swelling in toluene and different oils have been evaluated using standard techniques. Besides, the effects of different vulcanizing systems on the mechanical properties and degree of swelling of the vulcanized blends in toluene, as well as the resistance of the blends to the oils has been evaluated. It has been found that the type of rubber and the composition of blends clearly affect their resistance to oils. In contrast, the type of crosslinking and crosslinking density slightly affect the oil resistance of the corresponding vulcanizates.
2015
In this study, the effect of Treated Distillate Aromatic Extract (TDAE) was investigated in medium styrene/high vinyl solution styrene butadiene rubber (S-SBR) and high cis-polybutadiene rubber (BR). Three properties were evaluated: (i) molecular structure (polarity/aromaticity), (ii) molecular weight and (iii) chemical reactivity of the TDAE oil. The fore-mentioned properties of the oil allow the prediction of its behavior in a rubber compound. It was known from literature that the addition of oil causes a shift in the glass transition temperature (Tg) of the compound [2]. Therefore, the study was focused on the variation in the α-relaxation process or Tg of a rubber compound upon addition of TDAE. The conventional techniques for determination of Tg such as Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) as well as more sophisticated relaxation studies using Broadband Dielectric Spectroscopy (BDS) were used to characterize the TDAE-extended S-SBR and B...
Investigating the Influence of Rubber Seed Oil and Used Cooking Oil on Diesel
E3S web of conferences, 2022
In view of the multiple issues associated with fossil fuels, an environmentally friendly and economically feasible alternative energy source is required. While sufficient research has been conducted on diesel and single biodiesel blends, only a few studies on dual blended biodiesel have been conducted in this respect. The significance of blending waste cooking oil and rubber seed oil mixed with diesel at different proportions is investigated in the present research. At different braking power levels, the impacts of dual biodiesel (DB) performance and exhaust fumes on the stationary single-cylinder fourstroke air-cooled diesel engine with electrical loads were evaluated. The engine speed was held constant at 2800 rpm all through the testing. Each load was tested three times. Blend A had relatively better thermal and mechanical efficiency than diesel, based on experimental investigation results. Blends B and C were almost identical to the diesel values. Specific fuel consumption statistics for dual biodiesel blends were similar to diesel. The influence of different mixes on CO, CO2, HC, NOx, and smoke opacity were studied using emission tests. In contrast to diesel, the dual biodiesel blends produced more fumes, hydrocarbons, and nitrogen oxides. Dual biodiesel blends, on the other hand, have lesser emissions temperatures than diesel.
Fuel, 2012
Ethanol has become one of the main components for reformulated fuels because it is able to comply with environmental regulations. Biofuels have great advantages due to their physical and chemical characteristics, raw materials and production costs. However, they also have some disadvantages, mainly in terms of their compatibility with existing materials. Some components that are normally compatible with gasoline can be degraded by the presence of ethanol in fuel. The aim of this study was to evaluate the physical and chemical behavior of different polymeric materials typically used in autoparts, exposed in a mixture of gasoline and ethanol. To evaluate the resistance to degradation of the polymer samples, a continuous immersion test was performed according to SAE 1748. The effects of the 20% ethanol À80% gasoline mixture (E20) were examined by comparing changes in gain/loss of mass and by measuring the ShoreD hardness of the material at the end of exposure. The characterization of polymers was carried out before and after exposure by using the techniques of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). In general, polymeric materials submerged in gasoline showed negligible changes in mass. Samples of POM, HDPE, PA6/6 and PA6 exposed to E20 showed mass increases below 10%. The chemical structure and mechanical properties (hardness) of the evaluated polymers were not significantly affected by the E20 blend with the exception of PA66. Since significant changes were observed in the thermal properties of this polymer, it can be concluded that it was at the limit of compatibility.
Journal of Applied Polymer Science, 2013
The swelling of styrene-butadiene rubber (SBR) when exposed to organic solvents was measured and mathematically correlated to the toluene concentration in a complex mixture such as gasoline. This relation enables inferences to be made regarding the composition and quality criteria of the fuel and represents a new method to detect adulterations. Changes in the mass and volume were measured by gravimetric and hydrostatic techniques. A simplex-lattice experimental mixture design was carried out in mixtures with toluene, heptane, and type C gasoline (a blend of gasoline with ethanol) and the mass swelling was statically analyzed for 5 and 15 min of continuous immersion in the mixtures of the solvents. For the experimental design two cubic equations were obtained with a high value for R 2 -ajusted (>0.98) at 25 C 6 1 C correlating mass swelling of SBR and the content of solvents. For both immersion times, the greatest and most important effect over the mass swelling was the content of toluene, with the mass variations increasing proportionally with toluene content in the gasoline. The analysis of variance applied to the mass swelling data verified that it is possible to obtain good mathematical equations to associate the rubber swelling with the solvent composition and concentration.