内燃机气缸密封用缩合型室温硫化硅橡胶

采用XJ-201丝印油墨为基础胶,正硅酸乙酯为交联剂,催化剂A和催化剂C为催化剂,乙醇为抑制剂,乙二醇乙醚醋酸酯（CAC）为溶剂,通过对丝网印刷的操作时间、固化时间、力学性能的考察,确定内燃机气缸密封用缩合型室温硫化硅橡胶的基本配方为100 g XJ-201丝印油墨中,催化剂A为1.44 g,催化剂C为0.96 g,抑制剂为3.6 g,溶剂为4 g。该条件下丝网印刷的操作时间为30 min,固化时间为10 h,剪切强度为3.3 MPa,满足内燃机气缸密封用缩合型室温硫化硅橡胶产品性能的要求。     

Preparation and thermal degradation behavior of room temperature vulcanized silicone rubber-g-polyhedral oligomeric silsesquioxanes

Room temperature vulcanized (RTV) silicone rubber-g-polyhedral oligomeric silsesquioxanes (POSS) was prepared and its thermal degradation behavior and thermo-oxidative stability were investigated by thermogravimetric analysis (TGA). The results demonstrated that the chemical incorporation of POSS into polydimethylsiloxane (PDMS) chains significantly enhanced thermal stability of RTV silicon rubber in both nitrogen and air atmosphere. The degradation behavior was further monitored by TGA coupled with real time Fourier transform infrared spectra (FTIR), and the residues were characterized by FTIR and X-ray photoelectron spectroscopy (XPS). It was found that the remarkable improvement in thermal stability could be attributed to the following reasons: (1) the branched structure of RTV silicone rubber-g-POSS and interaction between POSS molecules and PDMS chains; (2) POSS traps generated and grafted or cross-linked structure formed; (3) intumescent ceramic protective barrier formed; (4) the perfect distribution of POSS in RTV silicone rubber-g-POSS.     

室温硫化水性硅橡胶粘接性研究

为了使水性硅橡胶具有实用价值,本文采用定性测试的方法,较系统地对有机锡催化体系室温硫化(RTV)水性硅橡胶粘接性进行了研究。结果表明,水性硅橡胶的粘接性随体系pH值的升高而提高;在一定范围内,水性硅橡胶的粘接性随催化剂用量或交联剂用量的减少而得到改善;加入适当的增黏剂、羟基稳定剂、或使用潜伏性活性基团的底涂剂都有助于改善水性硅橡胶的粘接性。     

Study on the structure and properties of RTV/FR-DOMt nanocomposites

The aim of our research was to study the effect of flame-retardant dendrimer modified organic montmorillonite (FR-DOMt) with different ratios on the structure and properties of room-temperature-vulcanised silicone rubber (RTV). The physical and mechanical properties of RTV nanocomposites were improved with the addition of FR-DOMt additives. The RTV nanocomposites exhibited better thermal stability. T_onset of RTV/FR-DOMt-3 was 310 °C, 100 °C higher than that of pure RTV. RTV/FR-DOMt-3 nanocomposite possessed the highest elongation at break, 500%. This was 46% higher than that of pure RTV. In addition, these RTV nanocomposites showed an increased FR behavior. By adding 3–15 phr of FR-DOMt into pure RTV matrix, a linear decrease of burning rate together with an increase of LOI values were obtained. SEM and TEM observations of RTV/FR-DOMt-3 demonstrated that the exfoliated silicate layers dispersed uniformly in this nanocomposite.     

加成型室温硫化硅橡胶口腔印模材料

加成型室温硫化硅橡胶印模材料可以用于口腔外科整形如假牙修复、烤瓷等整形术.其主要成分是乙烯基聚二甲基硅氧烷,故也称乙烯基聚二甲基硅氧烷(Vinyl Polydimethyl Siloxane,以下简称VPS)印模材料.其突出特点是印模精度高、尺寸稳定性好.概括介绍了VPS印模材料的物理和化学性能及其最新研究进展.     

提高绝缘子的可靠性及其降低成本的技术进展

论文介绍了2001年世界绝缘子大会的概况，就会议论文与报告，从生产、应用以及有待解决的问题等方面，评述了绝缘子、芯棒、硅橡胶、憎水性涂层等产品的新技术与新进展，并提出了我国绝缘子行业中存在的问题和努力的方向。     

特高压直流换流站支柱绝缘子设计

特高压直流换流站的外绝缘设计是特高压直流输电工程的关键技术之一,直接影响工程的安全可靠运行,文章主要讨论特高压换流站支柱绝缘子的选型和设计。首先统计了 我国±500 kV换流站外绝缘的运行情况,总结了±500 kV换流站加强外绝缘和防污闪的主要措施,并分析了室温硫化硅橡胶(room temperature vulcanized silicone rubber,RTV)和长效室温硫化硅橡胶涂料的性能特点。然后根据积污站测试结果对特高压换流站站址的污秽水平进行了预测,根据预测的污秽水平和实验室污耐压试验结果推导出其所需的爬电比距。最后,分析了不同型式支柱绝缘子的经济技术特点,以及国内外厂家的制造能力,推荐瓷涂RTV方案作为特高压直流换流站外绝缘的首选方案,并对瓷涂RTV绝缘子使用过程中的相关问题进行了探讨。     

对溶剂型室温硫化有机硅隔离剂的探讨

本文对溶剂型有机硅隔离剂的溶剂与硅橡胶,偶联剂和催化剂等进行了论述。分析了它们各自的特性与作用原理,以及它们对隔离性的影响,在此基础上提出了溶剂型室温硫化有机硅隔离剂的最佳配比。     

胺加速硅橡胶室温硫化的研究EI

证实了胺不是RTV硅橡胶缩合催化剂,但在二丁基二月桂酸锡存在下,伯胺或仲胺是RTV硅橡胶的促进剂。当二烷基胺用RTV硅橡胶硫化时,其活性随烷基碳原子数增加而增加。为了弄清楚胺加速硫化作用的机理,笔者用~1HNMR和IR研究了二已胺与二丁基二月桂酸锡的反应,实验结果表明:胺加速二丁基二月桂酸锡生成二丁基二羟基锡,而后者正是RTV硅橡胶硫化的真正催化剂。