Development of sealing compositions with nanostructure iron-based fillers

The possibility of utilizing nanopowders of iron and Fe-Co-Ni produced bu a thermochemical method in the fabrication of sealing composition materials is investigated. It is established that such hermetic sealing composition materials function reliably under extremal conditions and guarantee elevated strength of adhesion to the surface of the metal and high corrosion and temperature stability. __________ Translated from Poroshkaya Metallurgiya, Nos. 3–4(448), pp. 112–117, March–April, 2006.     

由对硝基苯甲醚制备对氨基苯甲醚的工艺研究

以硫磺和氢氧化钠为原料,制备多硫化钠,然后用多硫化钠还原对硝基苯甲醚合成对氨基苯甲醚。第一步反应在90℃下回流1h,硫磺的转化率可达100%;第二步反应在110℃下回流8h,对氨基苯甲醚的收率为96%,纯度为99%,副产品硫代硫酸钠的收率为92%,纯度为98%。     

带压垫片密封技术在我厂的应用

介绍了在化工生产中，对大的地漏点（大径法兰、管道等）应用不停车带压密封技术进行堵漏的原理及过程。     

以氨基笼型倍半硅氧烷为固化剂的环氧树脂灌封胶

用笼型β-氨乙基-γ-氨丙基倍半硅氧烷(CAAPOSS)和4,4-二氨基二苯醚(DDO)为固化剂,间苯二酚双缩水甘油醚为活性稀释剂,制备了双酚-A型环氧树脂灌封胶,并研究了胶粘剂各组分从而获得了较高的物理机械性能。测定了与碳钢的粘接强度,热性能和耐老化性能。结果表明,该胶粘剂是一种热稳定性好、耐高温、粘度低的优良结构胶粘剂。     

充油型脱醇型硅酮密封胶性能研究

研究了甲基硅油、低分子量聚丁烯、氢化烷烃油作为增塑剂用于脱醇型RTV-1硅酮胶对其性能的影响。结果表明:甲基硅油增塑剂对降低模量、提高位移能力效果明显;聚丁烯与聚硅氧烷相容性差,影响与基材的界面粘接;少量添加烷烃油能起到与甲基硅油类似的效果,但热失重超过10%,添加量增加对基材的粘结性变差,其它性能也大幅降低。     

密闭条件下使用的氟硅密封剂的制备

讨论了硫化体系，硫化剂用量，填料种类对在密闭条件下使用的氟硅密封剂耐热性能的影响，结果表明，采用硅氮烷低聚物作硫化剂，TiO2为补强填料，硅氟密封，剂在密闭环境中180℃高温下降解不明显，硫化后的密封剂仍保持一定的硬度和良好的弹性。     

Modification of polysulfide sealant with polysulfide polythio‐urethane‐urea

With a small amount of isocyanate‐terminated polysulfide (NCO‐PSF‐NCO) as additive, the commercial polysulfide‐based sealant had significant improvement in mechanical properties. The test results showed that 5% of NCO‐PSF‐NCO could help to rise 50% in the tensile strength and 27% in the ultimate elongation of the polysulfide sealant. The adhesive strength to substrates such as steel, epoxy‐coated or polyurethane‐coated surface also increased significantly. Dynamic mechanical thermal analysis and differential scanning calorimetry analysis revealed that formed polysulfide polythio‐urethane‐urea (polysulfide‐urea) contributed to a slight increase in the T_g of the polysulfide sealant. It might be due to the domains of polysulfide‐urea, which had effects of physical crosslinking and chain‐extending on the polysulfide sealant. However, the introduction of polysulfide‐urea structures had no appreciable influence on oil resistance of the polysulfide sealant. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

有机硅建筑密封剂老化机理研究

本文探讨了有机硅建筑密封剂潮气固化和降解的机理，并根据理想弹性体概念和理想弹性方程及Ｍａｘｗｅｌｌ模型建立了有机硅建筑密封剂在潮气中曝露时交联和降解的动力学模型。通过实验数据求得了动力学方程。结果表明，有机硅建筑密封剂在潮气中的性能变化呈现两个不可逆的简单的一级反应，即交联反应和降解反应，这两个反应的速度常数分别为ｋ１＝０．０２２４（１／天）和ｋ２＝０．０２７（１／天）。本方程的建立，为有机硅建筑     

RTV有机硅密封胶的耐介质性

通过介质浸泡试验研究了水、机油、汽油对有机硅密封胶的影响，采用初期耐压性衡量其密封性。试验表明，有机硅密封胶具有优异的耐水性和耐油密封性，但耐汽油性较差；重质碳酸钙可提高其耐油性，有机硅密封胶中的增塑剂在油类介质中会发生迁移。该类密封剂可用作机械部的就地成形垫圈。     

单组分室温硫化硅橡胶的配制(十五)

介绍了脱酰胺、脱羟胺型单组分室温硫化(RTV-1)硅橡胶的特点，以及脱酰胺／羟胺型(包括普通型、高粘接性型、耐水性型、超低模量型)、脱羟胺型(包括用含S-H基的硅氧烷或异氰酸酯作羟胺清除剂)、脱酰胺型(快干型、自流平型)及脱酰胺／酮肟型低模量RTV-1硅橡胶的配制。