基于斜面法试验研究SiO_2质量分数对RTV硅橡胶涂料性能的影响

Investigation into Influence of SiO_2 Mass Fraction on Coating Performance of RTV Silicone Rubber Based on Inclined Plane Test

针对室温硫化(roomtemperature vulcanization,RTV)硅橡胶涂料应用中存在的黏附力不强、涂层易划破的问题,提出通过添加二氧化硅来提高硅橡胶的机械强度,改善材料的耐电痕化和耐电蚀损性。为此,结合热导率的概念,通过斜面法试验讨论了二氧化硅对RTV硅橡胶性能的影响,试验中采用西安交通大学电力电子专用设备研究所研制的高精度交流漏电起痕试验装置配合自行研发的多路泄漏电流实时监测采集装置,对制备的3种RTV硅橡胶涂料试片(只添加二氧化硅,且二氧化硅质量分数为20%、30%、50%)按照GB/T6553—2003《评定在严酷环境条件下使用的电气绝缘材料耐电痕化和蚀损的试验方法》进行试验。结论为:二氧化硅质量分数越高的硅橡胶热导率越大,热量越容易传导,耐电痕化和耐电弧烧蚀性越强;二氧化硅含量高、热导率大的硅橡胶试片到达过流保护动作的临界状态时,其烧蚀区域面积和烧蚀深度都较低二氧化硅含量的试片大;二氧化硅填料的增加使硅橡胶电蚀损后憎水性恢复过程减慢。

To solve the problems of poor adhesion and easy scratching while applying coating of room temperature vulcanization（RTV） silicone rubber,the use of silica is proposed to improve the mechanical strength of silicone rubber as well as the material＇s resistance to electrical tracking and erosion.Therefore,combined with the concept of thermal conductivity,the influence of silica on performance of RTV silicone rubber is investigated by inclined plane test.High-precision AC tracking tester developed by Institute of Electrical and Electronic Equipment,Xi＇an Jiaotong University is used in the test together with independently developed multiple leakage current real-time monitoring and acquisition device,so as to test the three prepared RTV silicone rubber coating specimens（only adding silica,mass fractions thereof being 20%,30%,50%） according to GB/T 6553-2003 Test Methods for Evaluating Resistance to Tracking and Erosion of Electrical Insulating Materials Used under Severe Ambient Conditions.It is concluded that the higher the mass fraction of silica,the greater the thermal conductivity of silicone rubber,the easier the heat transfer,and the stronger the resistance to tracking and electrical arc erosion;when reaching the critical state that actuates the overcurrent protection,the silicone rubber specimen with high silica content and large thermal conductivity has greater eroded area and depth than the specimen with low silica content;the increase of silica filler slows down the hydrophobicity recovery process of eroded silicone rubber.