高低温循环条件下氟橡胶耐油介质老化性能

为了获得高低温循环条件下某种导弹用密封氟橡胶材料的老化机理,对某牌号的弹用密封氟橡胶试样进行了高低温循环油介质加速老化实验。对其在高低温油介质条件下的压缩永久变形、机械性能、微观形貌、分子结构、动态力学性能的变化规律进行了研究,同时计算了氟橡胶分子几个重要的化学键的离解能。结果表明:高低温循环下特种氟橡胶的最大拉伸强度与拉断伸长率随着循环周期数的增加逐渐降低,油介质中贮存的氟橡胶试样压缩永久变形率在老化前期逐渐增大,老化后期略有恢复,随着老化时间增长氟橡胶分子侧基分解,主链柔顺性增强。

Aging Properties of Fluororubber in Oil Medium Under High-Low Temperature Cyclic Environment

In order to obtain the aging mechanism of a certain kind of sealing fluororubber under high-low temperature cyclic conditions,the fluororubber seal ring was subjected to an accelerated aging test of high-low temperature conditions in oil medium.The changes of compression set,mechanical properties,microstructure, molecular structure and dynamic mechanical properties under the condition of temperature-changing oil medium were studied.The dissociation energy of several important chemical bonds of fluororubber molecules was calculated. The test results show that the maximum tensile strength and elongation at break of special fluororubber decrease with the increase of the number of cycles,and the compression set rate of fluororubber samples stored in oil medium increases gradually in the early stage of aging.The compression set rate of fluororubber samples slightly restored in the late stage of aging,as the aging time increases,the side groups of the fluororubber molecules decompose and the main chain flexibility increases.