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181.
采用丁基橡胶研制用于中空玻璃单道密封的热熔胶.研究主体树脂品种、增黏剂、改性剂、填料的类型及用量对材料性能的影响.实验采用正交方法对胶料成分进行配比,在开放式塑炼机的混炼下得到热熔密封胶胶料,并测得胶料与玻璃的黏接性、拉伸性及流变性.实验结果表明:加入具有良好增黏作用的低分子聚异丁烯以及石蜡,都有利于提高胶条的黏接性能,丁基橡胶对胶条的拉伸性能影响最大,加入少量石蜡,可以降低黏度,增加其流动性. 相似文献
182.
长春市燃煤供热锅炉运行及煤耗现状调查 总被引:1,自引:0,他引:1
我国严寒地区主要以燃煤供热锅炉为采暖热源,笔者通过实地走访长春市111座燃煤供热锅炉房,针对锅炉实际运行及煤耗的情况开展调研,并提出了节能方面存在的问题及解决的措施。 相似文献
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分析了当前中小氮肥厂合成氨工段出塔氨含量偏低的现象,提出用氨合成增效反应器来解决这一问题,并阐述了其应用前景。 相似文献
187.
Strong and durable adhesive bonds may be made between polytetrafluoroethylene (PTFE) and either cyanoacrylate (CA) or epoxy adhesives, if the PTFE surface is modified by the use of a “primer” such as triphenylphosphine (TPP) or diaminodiphenylmethane (DDM). The primer mixes with the PTFE surface, and the modified surface is then capable of forming an interphase, tens to hundreds of nanometers thick, where interpenetration of the adhesive and adherend occurs. Using CA adhesives, PTFE/CA/PTFE block compression shear bond strength (ASTM D4501-85) of over 10 MPa can be achieved, with failure occurring cohesively. Initial work with epoxy adhesives indicates that the use of DDM primer gives adhesive bonds comparable in strength with those produced by modification of the fluoropolymer surface by sodium naphthalenide. 相似文献
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Stress distributions and deformation of adhesive butt joints are analyzed by an elastoplastic finite element method when the joints of similar and dissimilar shafts are subjected to external bending moments. The effects of the ratio of Young's modulus for the adherends to that for an adhesive and the effects of the adhesive thickness on the interface stress distribution are investigated. Joint strength is predicted by using the elastoplastic interface stress distributions. It is found that the singular stress at the edge of the interfaces increases with an increase of the ratio of Young's modulus. Measurement of strains in joints and experiments on joint strength were conducted. The numerical results are in fairly good agreement with the experimental results. It is observed that the joint strength for dissimilar shafts are smaller than those for similar shafts. A fracture of dissimilar adhesive up-bonded shafts occurred from the interface of the adherend with smaller Young's modulus. It is seen that joint strength increases as the adhesive thickness increases. 相似文献
190.
The peel and tack properties of mixtures of polystyrene-block-polybutadiene-block-polystyrene (SBS) and a tackifier were investigated after these were crosslinked by ultraviolet (UV) irradiation at various amounts of benzophenone (BP) as a photoinitiator and trimethylolpropane mercaptopropionate (TRIS) as a crosslinking agent.The degree of crosslinking of polybutadiene (PB) block in the SBS mixture was qualitatively estimated from the amount of gel fraction as well as the change in the glass transition temperature of the PB block. The crosslinking of the PB block was done within 3 min after UV irradiation and the peel strength of crosslinked specimens was as low as 45[percnt] of specimens without crosslinking. Nano-tack and bulk tack properties as well as the surface tension of mixtures were measured depending upon amounts of BP and TRIS. 相似文献