The aging behaviors and mechanism of fluoroelastomer (FKM) under lubricating oil (FKM-O) and air (FKM-A, as a comparison) at elevated temperatures were studied from both physical and chemical viewpoints. The obvious changes of mechanical and swelling performances indicate that the coupling effect of lubricating oil and temperature causes more serious deterioration of FKM-O compared to that of FKM-A. Meanwhile, much stronger temperature dependence of both bulk properties and micro-structures for FKM-O is found. Three-stage physical diffusion process is defined in FKM-O due to the competition between oil diffusion and elastic retraction of network. FTIR results reveal that the dehydrofluorination reaction causes the fracture of C-F bonds and produces a large number of C-C bonds in the backbone. The coupling effect of oil medium and high temperature could accelerate the scission of C-C bonds and generate a series of fragments with different molecular sizes. The TGA results, crosslinking density V_e, and glass transition temperature T_g derived from different measurements coherently demonstrate the network destruction in the initial stage and the simultaneous reconstruction occurring at the final stage. The newly formed local network induced by reconstruction cannot compensate the break of the original rubber network and thus only provides lower tensile strength and thermal stability.

从物理和化学的角度研究了含氟弹性体（FKM）在润滑油（FKM-O）和空气（作为比较的FKM-A）下在高温下的老化行为和机理。机械性能和溶胀性能的明显变化表明，润滑油和温度的耦合作用比FKM-A引起FKM-O更严重的劣化。同时，发现FKM-O的整体性质和微观结构对温度的依赖性更强。由于油扩散和网络弹性收缩之间的竞争，FKM-O中定义了三阶段物理扩散过程。FTIR结果表明，脱氟化氢反应会导致CF键断裂，并在主链中产生大量CC键。油中和高温的耦合作用可以加速CC键的断裂，并产生一系列分子大小不同的片段。TGA结果，交联密度V _e和源自不同测量的玻璃化转变温度T _g一致地证明了在初始阶段的网络破坏和在最终阶段发生的同时重建。重建引起的新形成的局部网络无法补偿原始橡胶网络的断裂，因此只能提供较低的拉伸强度和热稳定性。