特种氟硅橡胶热空气老化的衰减全反射傅里叶变换红外光谱研究

Study on behavior of special fluorosilicone rubber in thermaloxidative aging process by attenuated total reflection Fourier transform infrared spectroscopy

通过衰减全反射傅里叶变换红外光谱(ATR-FTIR)分析了特种氟硅橡胶在热空气加速老化过程中微观结构的变化,研究了特种氟硅橡胶的耐老化性能,提出了特种氟硅橡胶的热氧老化机理。结果表明,特种氟硅橡胶在热空气老化过程中主链变化较小,其特征吸收峰可以作为ATR-FTIR定量分析的基准,而交联键和侧链三氟丙基基团的变化较明显;特种氟硅橡胶的拉伸强度和扯断伸长率随着老化时间的延长而不断下降,并且呈现出前期下降幅度小、后期下降幅度大的变化趋势,邵尔A硬度在老化的整个阶段没有明显的变化,特种氟硅橡胶具有良好的耐老化性能,其可能的老化机理是交联键的破坏和侧链的断裂。

The microstructure of special fluorosilicone rubber in the thermal-oxidative aging process was analyzed by attenuated total reflection Fourier transform infrared spectroscopy （ATR-FTIR）,the thermal aging resistance was studied,and the possible aging mechanisms were supposed.The results showed that after aged in a hot-air-oven for a long time,the special fluorosilicone rubber changed little in its main chain,the characteristic peak of which could be used as a reference for quantitative analysis of ATR-FTIR,but the crosslinking degree and the side chain trifluoropropyl groups changed significantly.The tensile strength and elongation at break decreased with increasing aging time,which showed a small decline in the early and a big drop in the late.While the Shore A hardness had no significant change during the entire period of aging,which indicated that the special fluorosilicone rubber had a good thermal aging resistance.The possible aging mechanism was supposed to be the crosslink destruction and side chain fracture.