TY - GEN A1 - Zaghdoudi, M. A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar A2 - Altenbach, H. A2 - Hitzler, L. A2 - Johlitz, M. A2 - Merkel, M. A2 - Öchsner, A. T1 - Analysis of Heterogeneous Ageing of HNBR O-Rings T2 - Lectures Notes on Advanced Structured Materials 2 N2 - Abstract Hydrogenated nitrile butadiene rubber (HNBR) elastomer was thermo-oxidatively aged at different temperatures up to 150 °C. Fourier transform infrared spectroscopy (FTIR), compression stress relaxation (CSR) and international rubber hardness degree (IRHD) microhardness were used to characterise the chemo-mechanical changes of HNBR O-rings during thermo-oxidative ageing. FTIR shows the development of carbonyl, methyl and ester groups but the nitrile content was not affected by ageing. The effect of sample geometry during CSR was investigated. CSR data were converted through integrated kinetic laws. The conversion has proven its sensibility to detect heterogeneous ageing. This was confirmed by the IRHD measure-ments across the section of O-rings. The influence of compression during ageing was assessed through IRHD measurements across the section of compressed and uncom-pressed aged O-rings. The DLO effect was more pronounced in compressed O-rings. By applying the model of Wise et al., theoretical IRHD and oxidation profiles were determined on the basis of IRHD experimental data of compressed O-rings. Good agreements between the experimental and the theoretical IRHD profiles in the core region were obtained. However, near the edge, the theoretical IRHD values were overestimated. PB - Springer Nature CY - Cham, Switzerland KW - Ageing KW - Rubber seals KW - Stress relaxation KW - Modelling PY - 2024 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/59769 AN - OPUS4-59769 SN - 978-3-031-49042-2 SN - 1869-8433 SP - 331 EP - 348 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany