有机硅橡胶热氧老化动力学的评价方法  

Evaluation method of thermal-oxidative aging kinetics of silicone rubber

作　　者：王志强 尚欣欣 杨楠 屈会芳 张长烨 Wang Zhiqiang;Shang Xinxin;Yang Nan;Qu Huifang;Zhang Changye(Tonsan Adhesive Inc.,Beijing 100041,China)

机构地区：[1]北京天山新材料技术有限公司,北京100041

出　　处：《中国胶粘剂》2021年第9期12-16,36,共6页China Adhesives

摘　　要：采用热氧加速老化法,探索了自制的有机硅橡胶在温度变化过程中的各种物理及化学变化的过程,并对其降解过程和使用寿命进行了评估。通过对硅橡胶不同老化时间的热重分析(TGA)测试,得到失重量-温度的曲线及其微熵曲线。利用动态热力分析(DMA)温度扫描的方法,研究了自制的有机硅橡胶在150、175和200℃三个不同温度下不同老化时间的动态热力学性质。研究结果表明:随着老化时间的增加,老化过程由解扣式降解为主导转变为重排式降解为主导。松弛时间τ与温度有关,因此改变温度就可以改变链段运动的松弛时间τ;通过改变温度,可有效地对有机硅橡胶的老化动力学进行评估。选择储能模量作为特性指标,利用Arrhenius速率常数外推模型二步法对该材料进行了使用寿命的评估,得到有机硅橡胶在常温(23℃)的使用寿命约为12年。The thermal-oxidative accelerated aging method was used to explore the various physical and chemical changes of self-made silicone rubber in the temperature change process,and its degradation process and service life were evaluated as well.The weight loss-temperature curve and its micro-entropy curve were obtained through the thermogravimetric analysis(TGA)test of the silicone rubber at different aging time.The dynamic thermodynamic properties of self-made silicone rubber at three different temperatures of 150,175 and 200℃for different aging time were studied by dynamic thermal analysis(DMA)temperature scanning method.The research results showed that with the increase of aging time,the aging process changed from unzipped degradation as dominant to rearrangement degradation as dominant.The relaxation timeτwas related to temperature,therefore,changing the temperature could change the relaxation timeτof change segment motion.The aging kinetics of silicone rubber could be effectively evaluated by changing the temperature.The storage modulus was selected as the characteristic index,and the service life of the material was evaluated by using the two-step method of Arrhenius rate constant extrapolation model.It was found that the service life of silicone rubber at room temperature(23℃)was about 12 years.

关 键 词：有机硅橡胶 热氧加速老化 Arrhenius速率常数 储能模量 使用寿命 

分 类 号：TQ433[化学工程]