Evaluation of the change in chemical structure of acrylonitrile butadiene rubber after high-pressure hydrogen exposure

Evaluation of hydrogen dissolved in rubber materials under high-pressure exposure using nuclear magnetic resonance

“…It was suggested that sorption sites in the material did not increase with the exposure pressures in this study up to 100 MPa, as the cross-link density or chemical structure of the exposed material did not change. 17 Thus, it may be reasonable to explain that the ratio change of [A] and [B] is not caused by the increase of sorption sites, but rather by the difference in the solubility of the hydrogen. Time dependency of the 1 H NMR spectra of dissolved hydrogen in NBR 1 H MAS solid-state NMR was employed to evaluate the hydrogen in the rubber in detail.…”

“…[13][14][15][16] We observed that hydrogen, an inactive and reductive gas, did not affect the chemical structure of acrylonitrile butadiene rubber (NBR), based on NMR, IR and Raman results. 17 Consequently, it was suggested that explosive failure by decompression was not caused by chemical structure change but by hydrogen dissolved in the materials. Therefore, it is important to analyze the characteristics and quantity of dissolved hydrogen to understand the explosive failure by decompression mechanism or swelling behavior of rubber materials.…”

Fracture Behaviour of Ethylene Propylene Rubber for Hydrogen Gas Sealing under High Pressure Hydrogen

“…Blister fracture and extrusion fracture due to volume increase of the rubber were identified as features of O-ring fracture. In the light of these findings, investigations aimed at developing high pressure hydrogen seals are currently focussing on the changes in structure and properties that accompany dissolution of hydrogen in rubber materials [9][10][11][12].…”

A Review on Applicability, Limitations, and Improvements of Polymeric Materials in High-Pressure Hydrogen Gas Atmospheres

“…However, the performance of those polymers depends on factors in operation, for example, application temperature, viscoelastic effects, and surrounding media. [9,70,71,76,110,111] Elevated working temperatures can alter the elastomer properties by aging, especially through chemical degradations, when the high-energy barriers for further reactions are surpassed; the degree of crosslink density and chain scissions are supposed to increase and the dominance of either mechanism depends on the rubber grade, the additives of the rubber recipe and the exposure temperature. Generally, the increase of cross-link density raises the T g and decreases the flexibility of polymer chains, which subsequently, increases the stiffness and tear resistance of the material.…”