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以液体聚硫橡胶为主要原料,通过添加镀镍石墨、导电炭黑等制备了一种新型导电聚硫密封剂。结果表明,此种导电聚硫密封剂体积电阻低于10Ω·cm,且经过热空气老化后导电性能保持稳定。 相似文献
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聚硫橡胶自1927年 J.C.帕特里克博士发现、研制并获得专利,已有几十年的历史。目前它成为世界密封剂的三大主干之一,每年消耗量达几千万吨。可见应用程度之广之深。国内虽有不少应用,但是相对之下,差距甚大。因此,有必要对此作一探讨。尤其是对液态聚硫橡胶密封剂(简称液态聚 相似文献
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研究了聚硫生胶、补强填料、树脂及偶联剂对聚硫密封剂力学性能及介电性能的影响,此外还对比了不同试样厚度对密封剂介电强度的影响.试验结果表明:未改性的液体聚硫橡胶的介电强度比改性聚硫橡胶高,综合考虑粘度、力学性能及工艺性能,选择改性胶与未改性胶共混作为生胶;气相二氧化硅作为补强填料时密封剂的介电性能比沉淀二氧化硅好;添加环氧树脂、酚醛树脂、环氧类偶联剂均可提高密封剂的介电强度,但需综合考虑密封剂的储存问题;密封剂试样厚度对其介电性能影响较大,可根据需要选择合适的材料厚度. 相似文献
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本文介绍聚硫橡胶密封剂与胶粘剂的特性及应用,对液体聚硫橡胶制备的硫化型密封剂,固体聚硫橡胶制备的不干型密封剂及环氧一聚硫橡胶粘剂的配方及制备工作了作叙述。 相似文献
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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 Tg 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 相似文献
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Sodium birnessite (Na2MnMnO13 · H2O), a layered manganese(IV) oxide–based phase, gives a liquid polysulfide cure that is too rapid for normal application when added at 10 pph polysulfide. The curing behavior of sodium birnessite added as 5 pph, 4 pph, and as a 5 : 5 pph mixture with an inert natural manganese dioxide was compared with that of a readily available manganese‐based commercial curing agent. The rate of cure at 5 and 4 pph was slower than the commercial agent at 10 pph and led to products with lower tensile strength. The cure with the 5 : 5 pph mixture gave a more rapid reproducible cure than that of the commercial agent, making a product with a higher tensile strength and lower elongation, which indicates better curing and higher crosslinking. The improved performance of sodium birnessite as a curing agent is consistent with the presence of Mn2+ in the lattice, creating vacancies in the Mn4+ O2− lattice and increasing the mobility of Mn4+ and its transport to the surface of the solid to oxidize the polysulfide. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1177–1181, 2000 相似文献
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偶联剂对改性聚硫密封剂粘接性能的影响 总被引:2,自引:0,他引:2
以改性液体聚硫橡胶为基胶,研究了硅烷偶联剂WD-50及螯合型钛酸酯偶联剂作为填料表面处理剂、直接加入密封剂体系、配制成粘接底胶及以上3种方式兼用对改性聚硫密封剂粘接性能的影响。结果表明,作为填料表面处理剂及直接添加到密封剂中都可以提高密封剂的剥离强度及内聚破坏率;配制成粘接底胶可以提高密封剂的内聚破坏率;采用WD-50作为轻质碳酸钙表面处理剂、同时在密封剂中加入一定量WD-50,并以WD-50和螯合型钛酸酯复合作为底胶可以使改性聚硫密封剂获得更理想的粘接性能。 相似文献