Swelling and mechanical properties of (acrylonitrile‐butadiene rubber)/(hydrogenated acrylonitrile‐butadiene rubber) blends with precipitated silica filled in gasohol fuels

Abstract

This work studied the effects of hydrogenated acrylonitrile-butadiene rubber (HNBR) and precipitated silica (PSi) loadings in acrylonitrile-butadiene rubber (NBR) filled with 60 parts per hundred of rubber (phr) of carbon black (CB) for oil-resistant seal applications in contact with gasohol fuel. The cure characteristics, mechanical properties, and swelling behavior of HNBR/NBR blends reinforced with PSi before and after immersion in ethanol-based oils (E10, E20, and E85) were then monitored. This work studied the effects of PSi loading in rubber compounds on the mechanical properties of the rubber blends. The results suggested that the scorch time of CB-filled NBR/HNBR was not affected by HNBR loading, but the cure time, Mooney viscosity, and torque difference increased with HNBR content. The swelling of the blends in E85 oil were relatively low compared with those in E10 and E20 oils. The recommended NBR/HNBR blend ratio for oilresistant applications was 50/50. Tensile strength and elongation at break before and after immersion in gasohol oils increased with HNBR loading, and the opposite effect was found for tensile modulus and hardness. PSi filler had no effect on scorch time, but decreased the cure time of the blends. The swelling level of the blends slightly decreased with increasing PSi content. The recommended silica content for optimum reinforcement for black-filled NBR/HNBR blend at 50/50 was 30 phr. The results in this work suggested that NBR/HNBR blends reinforced with 60 phr of CB and 30 phr of silica could be potentially used for rubber seals in contact with gasohol fuels. J. VINYL ADDIT. TECHNOL.,

Effect of the High-Pressure Hydrogen Gas Exposure in the Silica-Filled EPDM Sealing Composites with Different Silica Content

“…The connection of these devices requires the use of high-pressure hydrogen sealing. Rubber materials are used as seals for O-rings, gaskets, and packing for high-pressure hydrogen gas due to their low hydrogen permeation properties and excellent thermal, chemical resistance, and elasticity [ 6 , 7 , 8 ]. The representative rubber materials used as sealing devices for FCVs and HFSs are fluoroelastomer (FKM), acrylonitrile butadiene rubber (NBR), and ethylene propylene diene monomer (EPDM).…”

“…For example, the sealing devices made of FKM rubber are used for devices of FCVs and HFSs such as hydrogen compressors, which require an excellent resistance for hydrogen gas with high temperature and pressure. Because FKM exhibits excellent thermal and chemical resistance and gas barrier properties and the service temperature range of FKM is from −40 to 225 °C, which is much higher than that of other rubber materials [ 8 ], a few studies have investigated the effect of high-pressure hydrogen gas on the physical and mechanical properties of FKM composites and the long-term durability of FKM O-rings [ 9 , 10 ]. Furthermore, NBR is also widely used for seals and fuel hoses in FCVs and HFSs due to its excellent thermal and oil resistance.…”

Systematic investigation on the swelling behaviors of acrylonitrile‐butadiene rubber via solubility parameter and Flory‐Huggins interaction parameter

“…[3][4][5] In addition, swell induced aging of NBR after long-term immersed in liquid media is inevitable, and such aging will change the rubber's structure and composition, which will finally reduce the service life of the rubber product. [6][7][8] Actually, swelling of an elastomeric network is the result of two thermodynamic phenomena: an increase of entropy of the networksolvent system by introduction of small molecules of diluent, and a decrease of entropy of the polymer chains by the isotropic deformation. Furthermore, swelling disrupts the order of structure and increases heterogeneity of internal structures of polymer, and thus significant changes in structure and mechanical properties happen after 2 days of the elastomer immersed in various liquids.…”

Testing and evaluation of microstructure of organoclay in chlorosulfunated polyethylene nanocomposites by emphasis on solvent transport properties

“…The solution‐diffusion of organic solvents such as toluene, diesel, and kerosene into NR vulcanizates filled with palm kernel husk and carbon black (N330) was studied at ambient temperature . Use of swelling test in filled rubber blends was also the subject of some studies in rubber blend composites . Other researchers have investigated the effect of nanofillers such as nanoclay, nano‐CaCO 3 , and carbon black on the transport properties of rubbers .…”