This study investigates the combined effects of ionizing radiation and thermal treatments on the aging of siloxane foams containing small amounts of carbon nanofibers. Our siloxane foams were exposed to accelerated aging conditions for more than two years, resulting in very low dose rates. In addition, foams were aged under compressive load to evaluate the strength of the porous microstructure. Samples were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), Mössbauer, mass spectroscopy, electron paramagnetic resonance spectroscopy (EPR), solvent swelling, imaging techniques, uniaxial compressive load testing and tear testing. No significant changes in thermal stability or chemistry of the accelerated aged foam were observed, although gas evolution was detected. Changes in crystallization levels at low temperatures, microstructure, and mechanical properties were observed for foams with and without carbon nanofibers. In particular, foams aged under compressive load showed irreversible deformation of the porous microstructure. This study demonstrates that aging effects were enhanced when thermal and radiolysis were coupled together and that the addition of carbon nanofibers did not improve aging effects.

这项研究调查了电离辐射和热处理对含少量碳纳米纤维的硅氧烷泡沫老化的综合影响。我们的硅氧烷泡沫暴露于加速老化条件下超过两年，导致剂量率非常低。另外，将泡沫在压缩载荷下老化以评估多孔微结构的强度。通过差示扫描量热法（DSC），热重分析（TGA），傅里叶变换红外光谱（FTIR），核磁共振光谱（NMR），穆斯堡尔（Mössbauer），质谱，电子顺磁共振光谱（EPR），溶剂溶胀，成像对样品进行表征技术，单轴压缩载荷测试和撕裂测试。尽管检测到有气体逸出，但未观察到加速老化泡沫的热稳定性或化学性质有显着变化。对于具有和不具有碳纳米纤维的泡沫，观察到了在低温，微结构和机械性能下结晶水平的变化。特别地，在压缩载荷下老化的泡沫显示出多孔微结构的不可逆变形。这项研究表明，当热解和辐射分解结合在一起时，老化效果会增强，而添加碳纳米纤维并不能改善老化效果。在压缩载荷下老化的泡沫显示出微结构的不可逆变形。这项研究表明，当热解和辐射分解结合在一起时，老化效果会增强，而添加碳纳米纤维并不能改善老化效果。在压缩载荷下老化的泡沫显示出微结构的不可逆变形。这项研究表明，当热解和辐射分解结合在一起时，老化效果会增强，而添加碳纳米纤维并不能改善老化效果。