Morphological investigations on silica and carbon-black filled acrylonitrile butadiene rubber for sealings used in high-pressure H2 applications

• Published in: International journal of hydrogen energy Vol. 67; pp. 540 - 552
• Main Authors: Clute, Clara, Balasooriya, Winoj, Cano Murillo, Natalia, Theiler, Géraldine, Kaiser, Andreas, Fasching, Michael, Schwarz, Thomas, Hausberger, Andreas, Pinter, Gerald, Schlögl, Sandra
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.05.2024
• Subjects: Acrylonitrile butadiene rubber; Filler-rubber-interaction; High-pressure hydrogen gas; Rapid gas decompression (RGD); Sealing; Acrylonitrile butadiene rubber; Filler-rubber-interaction; Rapid gas decompression (RGD); Sealing; High-pressure hydrogen gas
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2024.04.133

To understand the effects of additives on the properties of rubber grades suitable for sealing applications in high-pressure H2 gas infrastructure, five acrylonitrile butadiene rubber (NBR) vulcanizates with different fillers and curing agents are investigated. Structure-property relationships of these grades are correlated with the additives and properties required for high-pressure gas atmospheres are evaluated. Further, the influence of the exposure to high-pressure hydrogen, i.e., hydrogen uptake and morphological changes after exposure, is evaluated. With the addition of a silica filler and a coupling agent for improved filler-matrix interfaces, similar overall properties, e.g. crosslink density, tensile strength, and storage modulus are obtained, compared to a carbon black (CB) filled grade. Density reduction after hydrogen exposure is significantly higher for CB-filled NBR, indicating higher hydrogen uptake in CB-filled rubber compared to silica filled NBR grades, or slower gas desorption. However, CB-filled specimens show to be less prone to filler migration than the silica-filled samples. •Effects of NBR formulations on properties for high-pressure gas systems were tested.•Functionalized silica enhances typical properties to a comparable range like CB.•The balance of additives results in suitable RGD performance.•Silica filled NBR shows lower H2 uptake compared to non-plasticized CB filled NBR.•Morphology of CB filled NBR is less affected by H2 than silica filled grades.