O-rings made of HNBR, EPDM and FKM were aged in the compressed and uncompressed state at 150 °C, 125 °C, 100 °C, 75 °C, 60 °C and 23 °C for aging times of up to five years. Hardness was measured and increased with aging time and temperature for HNBR and EPDM, but it remained practically constant for FKM. Indenter modulus measurements were performed on the lateral O-ring surface (that was free of DLO effects) to assess an influence of the compression during aging, but none was detected. The equilibrium compression set (CS) exhibited faster and stronger degradation than hardness and was used for lifetime predictions using the time-temperature superposition (TTS) principle. With an end-of-lifetime criterion of 70% CS, lifetimes of 4.5 years, 50 years and 526 years at 75 °C were estimated for HNBR, EPDM and FKM, respectively. The activation energies derived from an Arrhenius plot of the shift factors from the TTS were 85 kJ/mol, 99 kJ/mol and 78 kJ/mol for HNBR, EPDM and FKM, respectively, revealing that a higher activation energy does not necessarily mean that the material has a higher lifetime at lower temperatures. Furthermore, the measured lifetime of EPDM O-rings at 100 °C (5 years) was compared to that predicted on the basis of the lifetime at 150 °C as well as 125 °C using the corresponding shift factors. The error of the prediction was only ±4%. However, this precise prediction could only be achieved using the five-year long-term aging data. When using only data from aging times up to 0.5 years and 2 years, the lifetime of EPDM O-rings at 100 °C was underestimated by 31% and 22%, respectively.

由HNBR，EPDM和FKM制成的O形圈在压缩和未压缩状态下分别于150°C，125°C，100°C，75°C，60°C和23°C进行老化，老化时间长达五年。对于HNBR和EPDM，测量硬度并随老化时间和温度的增加而增加，但对于FKM，硬度实际上保持不变。在侧面O形环表面（没有DLO效应）进行压头模量测量，以评估老化过程中压缩的影响，但未检测到。平衡压缩永久变形（CS）表现出比硬度更快，更强的降解，并且使用时温度叠加（TTS）原理用于寿命预测。以70％CS的使用寿命终止标准，HNBR，EPDM和FKM分别在75°C下的寿命分别为4.5年，50年和526年。从TTS位移因子的Arrhenius曲线得出的活化能对于HNBR，EPDM和FKM分别为85 kJ / mol，99 kJ / mol和78 kJ / mol，这表明较高的活化能并不一定意味着该材料在较低温度下具有较高的使用寿命。此外，将EPDM O形圈在100°C（5年）下测得的寿命与使用相应位移因子在150°C和125°C下的寿命所预测的寿命进行了比较。预测误差仅为±4％。但是，只有使用五年的长期衰老数据才能实现这种精确的预测。仅使用老化时间长达0.5年和2年的数据时，EPDM O形圈在100°C下的寿命分别低估了31％和22％。