共查询到18条相似文献,搜索用时 93 毫秒
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介绍了一类新型有机硅聚合物主链掺杂氧原子聚硅烷的合成与性质.该类聚合物是通过氧原子有规律地插入聚硅烷主链,形成具有氧杂低聚硅烷的序列结构(-[(SiMe2)mO]n-).聚合物的主链呈现了聚硅烷以及聚硅氧烷的杂化体结构.通过对此类聚合物性质的研究,能够获得有关此类聚合物行为的知识,从而进一步促进人们对聚硅烷和聚硅氧烷化学性质的了解.总结了此类聚合物的两类有效合成方法:通过α,ω-二功能基封端的线性硅烷低聚体缩聚反应法以及氧杂环硅烷单体的开环聚合反应法,包括氧杂环硅烷单体的开环聚合平衡和反应机理.讨论了此类聚合物的表征、热稳定性及其结构形态.在结论部分展望了此类聚合物的预期应用前景. 相似文献
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以聚二甲基硅烷裂解制备的液态聚硅烷为原料,添加引发剂过氧化二苯甲酰合成聚碳硅烷,使液态聚硅烷合成聚碳硅烷的产率提高了20%~25%.利用FTIR和GPC对反应过程进行跟踪分析,利用元素分析,1H-NMR,13C-NMR,TG-DTA和XRD对产物的组成结构和性能进行了表征,提出了过氧化二苯甲酰对液态聚硅烷合成聚碳硅烷的促进反应机理.结果表明,过氧化二苯甲酰受热分解形成自由基,促进了液态聚硅烷中的Si—Si键断裂重排,同时也引发了小分子硅碳烷中的Si—H和Si—CH3键断裂生成Si—CH2—Si结构,使聚碳硅烷分子量长大,产率提高.同时过氧化二苯甲酰分解产生的苯基和苯甲酰氧基会作为端基或侧基引入到聚碳硅烷分子中,引起产物C、O含量的少许增加.但对聚碳硅烷高温烧结后的陶瓷收率没有显著影响. 相似文献
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几种含苯乙炔基的硅-硅链高聚物的研究 总被引:2,自引:0,他引:2
采用含苯乙炔基的二氯硅烷和另外几种二氯硅烷,通过在甲苯中钠缩合的方法,合成了六种含苯乙炔基的聚硅烷。测试了聚合物的红外光谱,紫外光谱和核磁共振谱,测定了聚合物本体及掺杂后的电阻率。聚硅烷还可与某些电子受体形成复合物,形成的复合物在紫外尤谱上都有新的吸收峰出现。 相似文献
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陶瓷先驱体聚合物的应用 总被引:1,自引:0,他引:1
概述了几种典型的陶瓷先驱体聚合物聚碳硅烷、聚硅氮烷、聚硅氧烷、聚硅烷等在陶瓷材料制备中的应用研究进展,重点阐述了在该领域所取得的研究成果,并针对目前存在的不足提出了今后的研究方向。 相似文献
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用密度泛函理论(DFT)和含时密度泛函理论(TD-DFT)对线型(饱和N-杂环化)和(苯并N-杂环化)低聚硅烷的电子结构和吸收光谱性质以及溶剂效应进行了比较研究.对各体系的基态电子结构在B3LYP/6-31G(d,p)水平上进行了全优化,讨论了电荷分布和前线分子轨道性质.在获得基态稳定构型的基础上,用B3LYP/6-311+G(d)方法计算了电子吸收光谱的性质,探讨了主链的线型增长和溶剂对电子吸收光谱的影响.结果表明,随着主链的增长,低聚硅烷的电子结构发生明显扭曲,在(苯并N-杂环化)聚硅烷中形成了邻近苯并N-杂环之间π-π堆积作用,有利于结构的稳定.两类低聚硅烷的吸收光谱都随着主链的增长而发生明显的红移,(苯并N-杂环化)聚硅烷最大吸收光谱红移幅度要比(饱和N-杂环化)聚硅烷大得多.溶剂效应使得光谱略向短波长移动,溶剂的极性改变对吸收波长的影响不明显. 相似文献
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R. D. Miller G. N. Fickes 《Journal of polymer science. Part A, Polymer chemistry》1990,28(6):1397-1411
High molecular weight block interrupt polysilane derivatives have been prepared by the condensation of a number of α,ω-dichloropolysilanes with some aromatic bis silanols. In this manner, polymers containing polysilane blocks of 2, 4, or 6 catenated silicon atoms have been prepared. The materials are thermally stable and the UV spectroscopic properties mimic those of the corresponding monomers. Although these materials bleach upon irradiation in the deep UV, surprisingly, the block interrupt polysilanes behave as negative resists upon exposure to 254 nm radiation. This behavior contrasts with that of standard polysilane homopolymers which usually function in a positive lithographic mode. 相似文献
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R. D. Miller G. N. Fickes 《Journal of polymer science. Part A, Polymer chemistry》1990,28(10):2665-2677
High molecular weight block interrupt polysilane derivatives have been prepared by the condensation of a number of α,ω-dichloropolysilanes with some aromatic bis silanols. In this manner, polymers containing polysilane blocks of 2, 4, or 6 catenated silicon atoms have been prepared. The materials are thermally stable and the UV spectroscopic properties mimic those of the corresponding monomers. Although these materials bleach upon irradiation in the deep UV, surprisingly, the block interrupt polysilanes behave as negative resists upon exposure to 254 nm radiation. This behavior contrasts with that of standard polysilane homopolymers which usually function in a positive lithographic mode. 相似文献
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Phifer CC Thomes WJ Simmons-Potter K Potter BG 《The Journal of chemical physics》2004,120(3):1613-1616
The first vacuum-ultraviolet spectrum of a polysilylene (chain-type polysilane) with aromatic substituents is presented. Assignments of the absorption bands of the model compound poly(methylphenylsilylene) are based on previous experimental data and theoretical electronic band structure calculations for poly(alkylsilylenes) and on ultraviolet spectra of phenyl-containing monomers and polymers. Although aryl orbitals mix with the sigma-conjugated orbitals located along the catenated silicon backbone, some transitions are largely localized on the phenyl groups. These assignments elucidate the nature of the bonding in polysilylenes and should be useful in understanding photodegradation mechanisms and in the design of related new optical materials. 相似文献
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Dual‐emissive polydiphenylsilane nanocomposite: effect of N,N′‐bis(4‐hydroxysalicylidene)‐1,2‐phenylenediamine‐Zn complex 下载免费PDF全文
Liviu Sacarescu Corneliu Cojocaru Rodinel Ardeleanu Maria Fortuna Gabriela Sacarescu Mihaela Simionescu 《先进技术聚合物》2016,27(1):115-124
The fluorescence properties of polysilane can be strongly influenced by creating new excited states that involve electronic transitions and the relaxation to the ground state. This work presents the optical effects obtained by doping a specially designed polydiphenylsilane copolymer with Zn complex of N,N′‐bis(4‐hydroxysalicylidene)‐1,2‐phenylenediamine. The nanocomposites have been prepared in solution by mixing the polymer with low amounts of Zn–salophen and using tetrahydrofuran as solvent. The ultraviolet–visible spectrum has shown the occurrence of an intermolecular charge transfer between polysilane and the metal complex. Photoluminescence studies have revealed an interesting dual emission profile of nanocomposite. The origin of this phenomenon has been evidenced by molecular modeling and simulation of the electronic transitions. The modeling results have unveiled a new low‐lying excited state due to intermolecular interactions. The thin films of nanocomposites have been drop‐casted from solutions. The obtained films have been studied by Transmission Electron Microscopy (TEM)‐Scanning Transmission Electron Microscopy (STEM)‐Energy Dispersive X‐ray analysis (EDX) to gain information on the film‐forming capacity and surface morphology. The results have revealed a high potential of such materials for fluorescence sensing applications. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Jeffrey S. Hrkach Krzysztof Matyjaszewski 《Journal of polymer science. Part A, Polymer chemistry》1994,32(10):1949-1956
The synthesis of γ;-methoxypropylmethyldichlorosilane, and its subsequent polymerization and copolymerization with di;-n;-hexyldichlorosilane through the reductive coupling with sodium has been accomplished. The resulting polymers contain methyl ether side groups that allow further synthetic transformations on the polysilane backbone. For poly (γ;-methoxypropylmethylsilylene) these groups impart solubility characteristics different than typical alkyl and aryl substituted polysilanes. These new polymers and copolymers have been characterized by GPC and 1H-, 13C-, and 29Si-NMR. © 1994 John Wiley & Sons, Inc. 相似文献
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Polysilanes were found to photoinitiate the polymerization of a variety of vinyl monomers including methyl methacrylate, styrene, ethyl acrylate and acrylic acid. Polymerization initiated by polysilane photolysis is rather insensitive to oxygen inhibition, which may make it especially suitable for polymerization of thin films. The initiation efficiency of poly(phenylmethylsilylene) in styrene was determined from dilatometry data to be 1 × 10?3. This rather low efficiency is counterbalanced by the very high extinction coefficient of polysilane polymers, ca. 4–8 × 103 per silicon atom. Possible reasons for the low initiation efficiency and reduced oxygen inhibition of polysilane photoinitiators are discussed. 相似文献