共查询到20条相似文献,搜索用时 140 毫秒
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发光二极管封装用有机硅材料(一) 总被引:4,自引:1,他引:3
介绍了发光二极管(LED)的特点.列举了LED用环氧/有机硅混合树脂封装料(加成型有机硅与环氧树脂混合体系、环氧改性聚有机硅氧烷与环氧化合物混合体系)、含环氧基环烷基硅树脂封装料的主要成分及配制,LED的制作及评价等;加成型苯基硅树脂封装料中含Si-H基硅氧烷低聚物作交联剂的苯基硅树脂、含Si-H基、苯基的硅氧烷低聚物作交联剂的苯基硅树脂封装料的主要成分及配制等. 相似文献
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特殊结构的有机硅表面活性剂(续) 总被引:1,自引:1,他引:0
介绍了阴离子型有机硅表面活性剂、含酚基或芳氨基的聚醚改性硅油、反应性聚有机硅氧烷/聚内酯共聚物、含糖基的有机硅表面活性剂的特点、结构、合成方法及应用。 相似文献
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A study of increasing the flexibility and lowering the internal stress of the cured epoxy resing was carried out by using polysiloxanes capped with functional groups and premaking polysiloxane particles with d = 1.1 μm and narrow distribution. Polysiloxanes capped with functional groups were prepared by the reaction of X-22-163B with bisphenol-A, hexanedioic acid, and decanedioic acid. Poly(dimethylsiloxane-b-arylester) was synthesized by the reaction of poly(dimethylsiloxane) (X-22-162C) with arylester oligomers. Polysiloxane particles were obtained by cycling the mixture of polysiloxanes containing a vinyl group and a?Si–H group, respectively, emulsifier, and water in homogenizer. When oily polysiloxanes were used to improve the flexibility of epoxy resin, good compatibility of polysiloxanes with epoxy resion, and high molecular weight capped with epoxy group favor the formation of small-sized particles and homogeneous dispersion in the cured matrix. Comparisons were made among the epoxy resing modified with oily polysiloxanes capped with different functional groups. The results indicate that lightly crosslinked polysiloxane particles with d = 1.1 μm and narrow distribution have the greatest increase of elongation and biggest decrease of internal stress. The reason for this is discussed. © 1994 John Wiley & Sons, Inc. 相似文献
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综述了聚硅氧烷改性环氧树脂的机理和方法,对几种环氧树脂增韧方法进行了比较。通过国内外的研究进展介绍了物理共混和化学共聚2种改性方法,证实化学共聚改性的产物性能更佳,最后对其发展进行了展望。 相似文献
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A synthesized polydimethylsiloxane containing an isocyanate group was used to improve the flexibility and to reduce the internal stress of epoxy resin cured with MDA (4,4′-methylene dianiline). The effect of polysiloxane content on the curing kinetics of a novolac-type epoxy modified with an isocyanate group was investigated. It was found that the modified epoxy resin showed significant improvement in impact strength. The polysiloxane containing isocyanate groups effectively depressed the internal stress of cured epoxy resins by reducing the flexural modulus and the coefficient of thermal expansion, while the glass transition temperature was increased. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2739–2747, 1999 相似文献
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The morphology and fracture toughness of epoxy resins modified with amino-terminated polydimethylsiloxane (ATPDMS), differing in their molecular weight, and the degree of the preliminary reaction in the melt state were investigated. Tetramethyl biphenol diglycidyl ether (TMBPDGE) was used as the base epoxy resin. The degree of preliminary reaction between epoxy and polysiloxane increased with the decrease of the molecular weight of polysiloxane in the melt state. When the low molecular weight polysiloxane (AT900) was mixed with high molecular weight polysiloxane in the preliminary reaction, the low molecular weight polysiloxane enhanced the compatibility between the epoxy resin and the high molecular weight polysiloxane and produced smaller size and narrow distribution of polysiloxane particles. The small and highly concentrated polysiloxane particles, as determined by scanning electron microscopy improved the fracture toughness of the epoxy resin. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 941–955, 1997 相似文献
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Polysiloxane‐modified epoxy resin aqueous dispersions were prepared by the reaction of amino‐polysiloxane (APS) with a graft epoxy resin that was synthesized with a diglycidyl ether of bisphenol A type epoxy resin and styrene/acrylic acid. The measurements of the epoxy values and FTIR spectra confirmed that this reaction really took place. The modified aqueous dispersion exhibits high viscosity, small particle size, and nearly the same surface tension as the unmodified one. Therefore, this indicates that the siloxane segments could be encapsulated into graft epoxy resin particles during the water dispersion process. For APS‐modified films, the thermal stability and water resistance are remarkably enhanced. Furthermore, lowering of the hardness and surface tension for these films was also observed and the surface composition was measured by X‐ray photoelectron spectroscopy. The experimental data indicate that the siloxane segments easily migrate onto the surface during the film formation process and finally enrich on the surface of the APS‐modified film. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 880–885, 2005 相似文献
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聚硅氧烷改性环氧树脂 总被引:8,自引:0,他引:8
本文综述了将聚硅氧烷引入到双酚-A型环氧树脂的四种途径,即,活性端基反应;利用硅氧烷偶联剂生成嵌段共聚物;取代聚硅氧烷部分侧基和预先制备聚硅氧烷粒子,并介绍了聚硅氧烷改性该种环氧树脂的固化动力学。 相似文献
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Songqi Ma Zhengfang Wang Chaohui Hu Chunyi Tang 《Polymer-Plastics Technology and Engineering》2013,52(5):467-473
In this paper, polyether-grafted-epoxide polysiloxane (FEPMS) was synthesized via hydrosilylation among poly(methylhydrosiloxane) (PMHS), allyl polyoxyethylene polyoxypropylene ether (F6) and allyl glycidyl ether to modify Diglycidyl Ether of Bisphenol A (DGEBA). The morphology, thermal properties, and toughness of all cured samples were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and impact testing. Results indicated that grafted polysiloxane can be well dispersed in epoxy matrix, and the epoxy resin modified with FEPMS at relatively low addition levels exhibited higher thermal properties and improved toughness than the neat epoxy resin. 相似文献
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有机硅改性双酚F环氧树脂热性能研究 总被引:2,自引:0,他引:2
以TMA和TGA研究了含酚羟基的有机烷氧基硅烷及3,3′,3″-三羟基苯氧基硅烷三缩水甘油醚等多种自行设计、合成的有机硅改性剂改性双酚F环氧树脂的热性能。研究结果表明,有机硅可降低改性树脂的线胀系数,但端环氧基脂肪族聚硅氧烷及含酚羟基的二官能度有机硅的加入均使固化物玻璃化温度降低10℃以上;含环氧基的多官能度有机硅改性剂3,3′,3″-三羟基苯氧基硅烷三缩水甘油醚的加入可使线胀系数降低约20%,内应力指数降低约20%,抗开裂指数提高50%以上,固化物玻璃化温度基本不变,热分解温度有较大幅度的提高,是一种理想的环氧树脂增韧改性剂,可用于电子封装等行业用环氧树脂的改性。 相似文献