白炭黑补强氟硅橡胶热空气老化机理研究

Study on the Hot Air Aging Mechanism of Silica Reinforced Fluorosilicone Rubber

目的研究热空气老化过程中白炭黑补强氟硅橡胶的老化机理。方法开展不同加速老化温度点下白炭黑补强氟硅橡胶热空气老化试验,对老化过程中材料的力学性能进行研究,同时采用热重分析、衰减全反射红外光谱、交联密度分析以及固体核磁等技术,对200℃热空气老化过程中材料的微观结构变化进行分析。结果低温环境中白炭黑氟硅橡胶拉伸强度和扯断伸长率变化较小,高温环境中变化趋势增大,邵尔A硬度在整个老化过程中没有明显变化。结论白炭黑补强氟硅橡胶的老化机理主要是交联键的断裂和侧链三氟丙基的分解,同时还可能伴随有部分主链的破坏。

Objective To study the hot air aging mechanism of silica reinforced fluorosilicone rubber. Methods Hot air aging experiments of silica reinforced fluorosilicone rubber were conducted at different accelerated aging temperature, and the mechanical properties of the material during the aging process were studied. Meanwhile, thermal analysis, ATR-FTIR, XPS, and crosslink density tester were used to investigate the microstructure changes of fluorosilicone rubber during the 200~C hot air aging process. Results The tensile strength and elongation retention rate at break changed slightly in low-temperature environment, while the changing trend increased in high-temperature environment. The Shore A hardness did not show significant changes during the whole aging process. Conclusion The possible aging mechanism of fluorosilicone rubber could be crosslink destruction, trifluoropropyl decomposition in side chain and partial fracture in main chain.