高压绝缘防污闪涂层的研究进展

室温硫化(RTV)硅橡胶以其独特的憎水性和憎水迁移性而被用作新型高压绝缘防污闪材料,但仍存在附着力差,强度弱,阻燃性差等缺陷。为提高RTV硅胶的防污闪作用,进一步开展相关的研究工作,综述了污闪产生的机制,RTV硅胶的组成及特点、研究与应用。在概述了国内外RTV硅胶研究近况和RTV硅胶的小分子憎水迁移机理后阐明了纳米技术有效提高RTV硅胶的机械性能和耐老化性能,阻燃剂(如氢氧化铝)改善RTV硅胶的耐漏电起痕性、阻燃性能等的效果。最后指出,进一步提高RTV硅胶的机械性能、电气性能、抗老化性能是今后研究工作的热点。     

高海拔地区750kV线路防污闪、防雨闪措施研究

我国第1条750kV输电线路不仅处于高海拔地区，而且该地区气候条件恶劣，环境染污问题严重。根据750kV输电线路所在的高海拔地区的气候环境特点，分析了外绝缘设备在高海拔地区的污闪问题，并通过试验证实了复合绝缘子和RTV涂料技术在高海拔低气压条件下的防污闪能力，分析了高海拔地区可能出现的气象条件对硅橡胶材料憎水性的影响，发现低温和高湿度对硅橡胶憎水性的影响比低气压的影响更显著。讨论了750kV变电设备上可能出现的雨闪问题，提出了提高相关设备防雨闪能力的建议措施。     

单组分RTV硅橡胶与PMMA粘结性能的研究

研究了采用丙烯酸混合单体改性硅油,预涂底胶和改善填料处理工艺等方法对单组分RTV硅橡胶与PMMA间粘结性能的影响.研究结果表明:通过用丙烯酸类混合单体改性硅油的方法,可以显著提高单组分RTV硅橡胶与PMMA间的粘结强度;当改性硅油含量为20%(质量分数,下同)且预涂正-氯丙基三甲氧基硅烷底胶时,单组分RTV硅橡胶与PMMA间的粘结强度可以达到0.86 MPa;当掺加9%疏水型SiO2并预涂正-氯丙基三甲氧基硅烷底胶时,则掺5?MA改性单组分RTV硅橡胶与PMMA间的粘结强度达到0.8 MPa.     

建筑用室温硫化硅酮密封胶间的相似与差别

阐述了建筑用室温硫化硅酮密封胶间的相似与差别     

单组分室温硫化硅橡胶在汽车工业中的应用

单组分室温硫化(RTV)硅橡胶被称为免垫密封胶或液体垫圈,具有装配工序简单、材料成本低廉,密封效果好等优点,在汽车制造工业中已经形成标准施工方法,得到越来越广泛的应用。本文主要介绍了RTV硅橡胶作为汽车免垫密封的使用要求,论述了RTV硅橡胶配方设计,分析了装配过程中的相关问题。     

Effects of ?CH2CH2CF3 on properties of RTV polysiloxane rubber: Processability,thermal stability,and oil/solvent resistance

Room temperature vulcanizing fluorosilicone rubbers (FSRs) were prepared from polydimethylsiloxane (PDMS), vinyl fluorosilicone‐oil (VFS‐oil), and precipitated silica (PDMS/VFS/SiO₂). Rheological tests showed appropriate processing condition could be obtained when shear rate > 10 s^?1. Mechanical tests indicated that tensile strength and elongation at break were not much affected by VFS‐oil and no decline was observed after being aged in 70 °C ASTM 1# oil. The ? CF₃ group could not only increase oil‐resistance, but also decrease surface energy, which were proved by ATR‐FTIR and contact angle tests. The PDMS oil immersion tests showed that the higher the content of VFS‐oil, the better oil resistance can be obtained. The solvent‐resistance tests indicated that the VFS‐oil improved resistance to nonpolar/low‐polar solvent. TGA results showed that the increasing content of VFS‐oil could slightly decrease FSRs' thermal stability but increase FSRs' residual mass ratio at 790°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39708.     

加成型室温硫化硅橡胶力学特性的影响规律

以端乙烯基硅油为基础胶、低含氢硅油为交联剂、处理气相法白炭黑为填料、铂-二乙烯基四甲基二硅氧烷配合物为催化剂,制备了加成型室温硫化硅橡胶。考察了端乙烯基硅油黏度、处理气相法白炭黑用量、含氢硅油中的S—iH基与乙烯基硅油中的SiCH CH2基的量之比(简称A值)对硅橡胶力学特性的影响。结果表明,随着端乙烯基硅油黏度的增加,硅橡胶的拉伸强度、拉断伸长率和撕裂强度分别出现峰值;处理气相法白炭黑使硅橡胶的硬度先增后降;较佳工艺为:端乙烯基聚硅氧烷的黏度为5 P.as、处理气相法白炭黑用量为25份(按乙烯基硅油用量为100份计)、A值在1～3.6之间。按此条件制成的硅橡胶的邵尔A硬度为34度、拉伸强度4.78～5.09MPa、撕裂强度4.97 kN/m、拉断伸长率为107%。     

沿室温硫化硅橡胶表面及瓷表面染污放电现象的研究

在绝缘子表面涂覆一层憎水涂料,可显著提高绝缘子的耐污闪能力,实践证明这是防止污闪事故的一项有效措施。室温硫化硅橡胶涂料是一种新型防污、憎水、长效涂料,与常用涂料相比,室温硫化硅橡胶涂料具有涂覆简单、维护方便、寿命长的特点,目前已在我国许多地方投入使用。为了更好地了解室温硫化硅橡胶涂料的耐污闪能力,本文借助高速摄相机,拍摄了沿室温硫化硅橡胶表面和瓷表面污闪放电的全过程。通过照片,可以看出沿室温硫化硅橡胶涂料表面的污闪过程明显不同于沿瓷表面的污闪过程,借助记录波形并结合理论分析,揭示了两者不同放电现象的本质差别。     

乙烯基三异丙烯氧基硅烷的合成研究

为了获得脱丙酮型RTV硅橡胶的优良交联剂,实验合成了乙烯基三异丙烯氧基硅烷。以氯化亚铜为催化剂,三乙胺为缚酸剂,丙酮与乙烯基三氯硅烷为原料反应制取乙烯基三异丙烯氧基硅烷。并对其结构进行分析表征。同时研究了反应时间、加料速度和温度、不同溶剂、反应物料配比等因素对反应收率的影响。结果表明以上几个因素对产物收率都有显著影响,实验确定了反应工艺路线,产物乙烯基三异丙烯氧基硅烷的平均收率可达45.7%。     

Effect of Surface Roughness on the Adhesive Strength of the Heat-Resistant Adhesive RTV88

Heat-resistant adhesive RTV88 is a hyper-elastic material and so far there have been little research on using RTV88 in adhesive joints. In this study, the effect of surface roughness on the adhesive strength of RTV88 was examined. Aluminum adherends were first sandblasted in order to generate rough surfaces, and then tensile–shear tests on Al/RTV88 single lap joints were performed. The shear strength was shown to be influenced by surface roughness. Peel failure was dominant when the surface roughness was at a low level. However, cohesive failure was the major type of failure when the surface roughness was at a high level. Effective area, peel failure area, and cohesive failure area were introduced to explain the effects of surface roughness on the adhesive strength. An empirical relation for the failure force was proposed, based on these parameters. Tensile tests of the RTV88 bonding was performed in order to obtain the necessary data. Finally, the empirical relation for the failure force was verified by tensile–shear test results.