FX-4氟橡胶的老化行为研究

Aging Behavior of FX-4 Fluororubber

目的研究FX-4氟橡胶在不同工况条件下的老化行为,为工程实践中科学评估装备使用寿命提供依据。方法基于某装备对FX-4氟橡胶材料的使用要求,设计5种模拟工作状态条件的老化试验,通过观测样品外观形貌、力学、化学结构、打压密封等性能变化,研究FX-4氟橡胶在不同温度、不同介质和不同应变作用下的老化行为。结果经过9000 h老化试验,FX-4氟橡胶的压缩永久变形表现出明显增加的趋势,且增长速率呈现出先增大、再放缓、随后再次增大的变化规律。分解温度由508℃提升为520℃左右,表面结晶度和内部结晶度由61.7%分别下降为37%和48%左右,表明老化损伤由样品表面逐渐向内部扩展。分子结构没有发生根本改变,打压密封功能良好。结论经过9000 h老化试验后,FX-4氟橡胶出现不同程度的性能老化,但仍具备良好的密封性能,可正常使用。

The work aims to study the aging behavior of FX-4 fluororubber under different working conditions to provide a scientific basis for assessing life of equipment in engineering practice.Based on the requirements of a certain equipment for the use of FX-4 fluororubber material,five aging tests were designed to simulate the working conditions.The aging behavior of FX-4 fluororubber under different temperature,media and strain was studied by observing the changes of appearance,mechanical properties,chemical structure,sealability,etc.After 9000 hours of aging test,the compression set of FX-4 fluororubber showed an obvious increase trend,and the growth rate first increased,then slowed down and finally increased again.The decomposition temperature increased from 508℃to about 520℃.The surface crystallinity and internal crystallinity decreased from 61.7%to about 37%and 48%respectively,indicating that the aging damage gradually extended from the surface to the interior of the sample.The molecular structure did not change fundamentally,and the sealability was not damaged.After 9000 hours of aging test,FX-4 fluororubber has different degrees of aging,but still has good sealability and can be used normally.