共查询到19条相似文献,搜索用时 62 毫秒
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γ-巯丙基三乙氧基硅烷用气相法二氧化硅固载,再与氯亚铂酸钾作用,合成了聚γ-巯丙基奎氧烷铂(Ⅱ)配合物。研究了该了该梧全物对烯烃与三乙氧基硅烷的硅氢加成反应的催化特性。 相似文献
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活性炭负载壳聚糖络合铂配合物催化硅氢加成反应 总被引:1,自引:0,他引:1
以活性炭为载体,将壳聚糖(CS)负载到活性炭上得到复合载体,利用CS对Pt的螯合作用,制备活性炭负载CS络合Pt配合物催化剂(AC—CS—Pt),并考察了AC—CS—Pt催化剂催化烯烃与三乙氧基硅烷加成反应性能。采用X-射线衍射(XRD)、红外光谱(IR)和热重分析(TG)对AC—CS—Pt进行了表征,结果表明Pt与CS氨基N原子配位形成Pt—N配位键。对辛烯硅氢加成反应,AC—CS—Pt催化剂显示高活性和极好的产物选择性,β-加成产物的选择性达99%;具有良好的重复使用性能,AC—CS—Pt催化剂经简单过滤分离后,可连续使用14次而活性没有明显下降。 相似文献
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将壳聚糖(CS)负载到碳纳米管(CNT)上得到CNT-CS,再与Pt配位,制得CNT负载CS络合铂配合物(CNT-CS-Pt).将后者用作烯丙基缩水甘油醚和三乙氧基硅烷的硅氢加成反应的催化剂,并考察了该配合物的催化性能.结果表明,Pt与CS中的N原子配位形成Pt-N配位键;该催化剂在烯丙基缩水甘油醚和三乙氧基硅烷的反应中表现出极好的区域选择性及良好的催化活性,β-加成产物的选择性为100%,130 ℃下反应180 min,产物的收率达到70.4%.该催化剂可通过简单的方法回收但重复使用性能有一定下降,重复使用4次后产物的收率下降到24.0%.并对催化机理进行了初步的探讨. 相似文献
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不饱和烃硅氢加成催化剂固载化研究进展 总被引:1,自引:2,他引:1
综述了各类负载过渡金属的催化剂体系及其在不饱和烃硅氢加成反应中的应用。负载过渡金属的催化剂具有良好的可回收性和选择性,研究主要集中在开发价廉、使用安全、环境友好和高催化性能的活性炭、氧化物或有机聚合物等负载过渡金属催化剂,并取得很好的结果。 相似文献
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研究了硅橡胶硅氢加成硫化的有效控制问题。在无阻滞剂存在的情况下,硅氢加成反应30℃下6h内可发生凝胶化,80℃下10min内即完成硫化;在氢过氧化异丙苯存在下,交联反应在温度低于60℃时难于进行,但在100℃下10min内完成硫化;对苯骈三氮唑而言,相应的温度分别是100℃和140℃。 相似文献
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烯丙基硅(氧)烷铂配合物硅氢加成催化剂的研究 总被引:11,自引:1,他引:11
通式为(CH2 CHCH2) nSiR(4- n) ( n = 2 ,3 ,4 ;R= Me ,Ph) 的烯丙基硅烷以及1 ,3 二烯丙基 四甲基二硅氧烷(DATM) 经由Grignard 反应制备,它们再与氯铂酸反应制备出相应的标题配合物,这种配合物可用做硅氢加成催化剂。研究发现在氯丙烯与硅氯仿的加成反应中,TAS( n = 4) 、DMDA(n = 2 ,R= Me) 、MTA( n = 3 ,R= Me) 和DATM 的铂配合物的活性都比氯铂酸大。同时还讨论了几种铂配合物催化剂对含氢硅油与乙烯基硅橡胶的加成反应活性,发现不同催化剂的活性各不相同。 相似文献
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硅氢加成反应是合成有机硅材料最重要的途径之一,铂催化剂作为其应用最广的催化剂,具有重要的意义。本文首先介绍了硅氢加成反应机理的研究现状;分析了聚合物长链段铂配合物、含多个铂原子铂簇化合物及N-杂环卡宾铂配合物均相铂催化剂的研究进展,致力于改善均相催化剂催化选择性差、催化活性难以控制等缺点;分别阐述了不同铂催化剂载体如无机二氧化硅、炭载体、金属氧化物、有机高分子、固载液等作为铂催化剂载体的优点,负载铂催化剂具有可回收、产物选择性好的优点,有效解决了工业上铂损失的问题;最后对铂催化硅氢加成反应的发展趋势进行了展望分析,铂负载能力的提高、铂负载催化剂的分离、硅氢加成反应的原理、催化范围的扩大等均是今后研究的重要方向。 相似文献
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Optically clear silicone/epoxy hybrid resins were synthesized. The silicone resin (SiR) carrying Si? H, Si? CH?CH2 and Si? OH groups was prepared by hydrolytic condensation. The blends of SiR and diglycidyl ether of hydrogenated bisphenol A (DGEHBA) were cured through platinum‐catalyzed hydrosilylation and aluminium acetylacetonate‐catalyzed polymerization. The curing process was studied using differential scanning calorimetry and rigid‐body pendulum rheometry. It was found that the ratio of SiR to DGEHBA plays a major role in the curing process. The Si? OH groups of SiR assist polymerization of DGEHBA, and react with the epoxy resin to prevent phase separation. The cured hybrid resins are single‐phase materials with a transmittance of about 87% at 400 nm for a thickness of 3 mm using air as reference. UV resistance and thermal stability of the hybrids are largely dependent on the composition. The adhesive strength of the SiRs can be significantly improved by a small fraction of DGEHBA, with a marginal influence on UV resistance. However, increasing the epoxy proportion has a marked negative influence on thermal stability. Compounding stabilizers, especially thermal stabilizers, are essential, in particular for high epoxy content, if the hybrids are to be used for high‐brightness light‐emitting diode packaging. Copyright © 2011 Society of Chemical Industry 相似文献
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MDI/有机硅预聚体改性环氧树脂的研究 总被引:4,自引:0,他引:4
4,4′-二苯基甲烷二异氰酸酯(MDI)与双羟基聚甲基苯基硅氧烷分子结构中的羟基反应制得—NCO封端的预聚体,再将该预聚体与环氧树脂反应,合成了有机硅树脂改性的环氧树脂;以氨基树脂为固化剂制得有机硅改性环氧树脂涂层。用DTA-TG技术研究了其耐热性能,用EIS技术比较了改性产物涂层与环氧树脂涂层的耐腐蚀性能,根据国标GB/T1720—1979测定了改性产物涂层的附着力。结果表明:改性产物能耐420℃左右的温度,而且其涂层的耐腐蚀性能要优于环氧树脂,附着力随有机硅含量的增加略有降低,有机硅质量分数为25%~30%时,附着力都在2级以上。 相似文献
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Kexue Pan Hongqiang Li Xuejun Lai Zhonghua Chen Guangqiang Liang 《Journal of Adhesion Science and Technology》2016,30(24):2699-2709
A novel phenyl silicone resin with epoxy and acrylate group (PSREA) was successfully synthesized via the non-hydrolytic sol-gel condensation reaction of 3-glycidoxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, and diphenylsilanediol, and was employed as the adhesion promoter for addition-cure silicone encapsulant (ASE) with high refractive index. The structure of PSREA was confirmed by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and 29Si nuclear magnetic resonance spectroscopy. The influence of PSREA on the properties of ASE was studied. It was found that PSREA could markedly enhance the adhesion strength of ASE to aluminum (Al) and poly(p-phenylene terephthamide) (PPA) substrate. When the content of PSREA was 1.5 phr, the shear strength of ASE was 4.43 and 2.27 MPa for Al and PPA substrate, which was about 71 and 266% higher than that of ASE without the adhesion promoter, respectively. In addition, PSREA had little effect on the mechanical properties, refractive index, and viscosity of ASE. 相似文献
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Silicone rubber particles with different degrees of crosslinking were prepared. Silicone oils containing Si—H groups and vinyl groups were reacted at various mol ratios in their composite emulsions. Epoxy resin was modified using these particles and the results indicated that the content of the silicone rubber particles, the crosslinking degree of the rubber particles, and the addition of a coupling agent affected the properties of the modified epoxy resins. The influence of the coupling agent depends on the crosslinking degree of the silicone rubber particles. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 619–625, 1998 相似文献
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MQ硅树脂/纳米TiO_2复合改性环氧树脂的结构与性能 总被引:1,自引:1,他引:1
以环氧树脂(EP)为基体树脂,以MQ硅树脂和纳米TiO_2(nano-TiO_2)同时作为EP的增韧改性剂,由此制备了nano-TiO_2/MQ硅树脂/EP复合材料。研究结果表明:MQ硅树脂已成功接枝在EP分子链上;当m(MQ硅树脂):m(nano-TiO_2):m(EP)=15:3:100时,nano-TiO_2/MQ硅树脂/EP复合体系的耐热性能明显提高,拉伸强度和冲击强度分别提高了66.6%和68.1%,其断面呈韧性断裂特征。 相似文献