Mechanical properties of aramid fiber and carbon black filled hydrogenated nitrile rubber for packer compounds

Abstract

For the use in packer elements for oil exploration, rubber materials are required that can withstand high mechanical loads, high temperatures, and aggressive chemical media. To fulfill these demands, we designed composites of hydrogenated acrylonitrile butadiene rubber filled with both carbon black and short cut aramid fibers. Scanning electron micrographs indicate a strong connection between the resorcinol formaldehyde latex fiber coating and the peroxide-cured rubber matrix. During the preparation of the test specimens, especially care was taken to obtain samples with very well-defined fiber orientations. We studied the effect of fiber anisotropy on the hardness and on the mechanical properties under uniaxial elongation and cyclic compression at room temperature and 1508C. The strongest reinforcing effect is observed when the fibers are oriented along the main direction of deformation. For tensile test, this is the case, as expected, for fibers oriented parallel to elongation. For compression tests on cylindrical specimens, we find that the fiber orientation perpendicular to compression direction is most effective. At 20-40% strain, tensile tests exhibit a pronounced yield stress which is likely the result of the loss of adhesion between the rubber matrix and the fibers. Repeated loading and unloading compression tests reveal a considerable stress softening effect between the first and second cycle for fiber-filled composites. At 1508C, the rubber composites soften considerably, but small amounts of fiber still induce a significant reinforcement. POLYM. COMPOS., 00:000-000, FIG. 9. SEM-Micrographs of a RFL-coated aramid fiber (a), a fiber located at the fracture surface of a tensile test specimen with fibers oriented in L-direction (b), and fracture surfaces of composites with 80 phr CB, 6 phr peroxide, and 6 phr AF with fibers oriented in L-and T-orientation, (c) and (d), respectively.

Aramid pulp reinforced hydrogenated nitrile butadiene rubber composites with ionic liquid compatibilizers

“…Rubber products are currently used in the automotive sector and other important fields of application . For instance, short synthetic fiber‐reinforced rubbers are being applied in sealing products, such as gaskets and packers . Packers are widely employed in very harsh environments, at high pressures and high temperatures, for oil and gas exploration .…”

“…For instance, short synthetic fiber‐reinforced rubbers are being applied in sealing products, such as gaskets and packers . Packers are widely employed in very harsh environments, at high pressures and high temperatures, for oil and gas exploration . In most applications, rubbers such as hydrogenated nitrile butadiene rubber (HNBR) are typically reinforced with high loadings of carbon black (CB) particles to obtain the desirable levels of stiffness and mechanical strength .…”

“…Packers are widely employed in very harsh environments, at high pressures and high temperatures, for oil and gas exploration . In most applications, rubbers such as hydrogenated nitrile butadiene rubber (HNBR) are typically reinforced with high loadings of carbon black (CB) particles to obtain the desirable levels of stiffness and mechanical strength . Since CB‐CB interactions can be more temperature dependent than CB‐HNBR interactions, both tensile and compressive strength may be compromised .…”

“…3 Since CB-CB interactions can be more temperature dependent than CB-HNBR interactions, both tensile and compressive strength may be compromised. 3 As a consequence, CB-filled HNBR composites cannot fully meet the requirements for packer elements. Considering also that the production of CB is high-energy demanding and its polluting potential is significant, its complete or partial replacement by another more efficient reinforcing material could be relevant for the rubber industry.…”

Experimental study on application characteristics of zeolite/water stuffing for the nanofluidic packer rubber

“…Gang Hu et al 17 conducted constitutive experiments on three kinds of rubber materials and optimized their constitutive models. Xiaozhen He et al 18 improve the hardness, and tensile and compression modulus of the rubber by filling short cut aramid fibers in a hydrogenated acrylonitrile butadiene rubber (HNBR) composite.…”