湿热环境苯基阻尼硅橡胶加速老化与寿命预测研究

研究了苯基阻尼硅橡胶的湿热老化过程，重点考察了其拉伸性能、阻尼性能和压缩回弹性能。对于拉伸性能，实验研究表明材料拉伸模量和100%定伸应力均随着温度或者湿度的上升而逐渐提高。对于阻尼性能，损耗系数随着温度或者湿度的上升而逐渐下降。对于压缩回弹性能，压缩永久变形随着温度或者湿度的上升而逐渐上升。另外，温度对苯基硅橡胶性能的影响大于湿度。这主要归因于老化过程中同时发生了侧基氧化和水解，进而导致分子链交联和断裂同时发生。相比于分子链断裂，分子链交联占据了主导作用。最后，采用Peck模型预测了不同温湿度环境下苯基硅橡胶的贮存寿命。由于阻尼性能决定了苯基硅橡胶的减振性能，因此将损耗系数作为评价特征参数。结果表明，在25 ℃下，当相对湿度在80%~40%间变动时，苯基硅橡胶的寿命在18~39 a间变化。此研究有助于进一步理解苯基硅橡胶的老化过程，并且提供了不同湿热环境下苯基阻尼硅橡胶寿命预测的方法。

Rearch on the Accelerated Aging and Life Prediction of Phenyl Silicone Rubber in the Environments of Heat and Humidity

The heat-humidity aging process of phenyl silicone rubber is studied， focusing on its tensile， damping， and compression rebound properties. For tensile properties， experimental studies have shown that the material tensile modulus and 100% fixed elongation stress gradually increases with the rise of temperature or humidity.For the damping property， the loss factor gradually decline with the increase of the temperature or the humidity.For the compression rebound property， the compression compression permanent deformation gradually increases with the increase of the temperature or humidity. Moreover， the effect of the temperature on the properties of phenyl silicone rubber is more significant than that of the relative humidity. This is mainly due to the simultaneous occurrence of side group oxidation and hydrolysis during the aging process， which leads to the simultaneous occurrence of molecular chain crosslinking and breaking. Compared with molecular chain breaking， molecular chain crosslinking plays a dominant role. Finally， the storage life of phenyl silicone rubber under different temperature and humidity environments is predicted using the Peck model.Since the damping performance determines the vibration reduction performance of phenyl silicone rubber， the loss coefficient is used as an evaluation characteristic parameter. The results show that at 25 ℃， when the relative humidity changes between 80% and 40%， the life of phenyl silicone rubber changes between 18 and 39 a. This study helps to further understand the aging process of phenyl silicone rubber and provides a method for predicting the life of phenyl damping silicone rubber under different humid and hot environments.