Cyclopolymerization of dipropargylsilanes by transition-metal catalysts

Kim, Yun Hi; Gal, Yeong Soon; Kim, Un Young; Choi, Sung-Mo

doi:10.1021/ma00185a017

Cited by 41 publications

(14 citation statements)

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“…Polymers possessing an alternating arrangement of a π‐conjugated unit 83 such as phenylene, 84 ethenylene, 85–87 and a sil(an)ylene unit in the backbone were synthesized by coupling reactions, 86,88 thermal cyclopolymerization 89,90 and a variety of ring‐opening polymerization (ROP) reactions including anionic, 91–95 thermolytic, and catalytic coordination techniques, 96 each with some limitations.…”

Section: Preceramic Polymer Synthesismentioning

confidence: 99%

Polymer‐Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

Colombo

Mera

Riedel

et al. 2010

Journal of the American Ceramic Society

1,554

582

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Preceramic polymers were proposed over 30 years ago as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics (PDCs). The polymer to ceramic transformation process enabled significant technological breakthroughs in ceramic science and technology, such as the development of ceramic fibers, coatings, or ceramics stable at ultrahigh temperatures (up to 20001C) with respect to decomposition, crystallization, phase separation, and creep. In recent years, several important advances have been achieved such as the discovery of a variety of functional properties associated with PDCs. Moreover, novel insights into their structure at the nanoscale level have contributed to the fundamental understanding of the various useful and unique features of PDCs related to their high chemical durability or high creep resistance or semiconducting behavior. From the processing point of view, preceramic polymers have been used as reactive binders to produce technical ceramics, they have been manipulated to allow for the formation of ordered pores in the meso-range, they have been tested for joining advanced ceramic components, and have been processed into bulk or macroporous components. Consequently, possible fields of applications of PDCs have been extended significantly by the recent research and development activities. Several key engineering fields suitable for application of PDCs include high-temperature-resistant materials (energy materials, automotive, aerospace, etc.), hard materials, chemical engineering (catalyst support, food- and biotechnology, etc.), or functional materials in electrical engineering as well as in micro/ nanoelectronics. The science and technological development of PDCs are highly interdisciplinary, at the forefront of micro- and nanoscience and technology, with expertise provided by chemists, physicists, mineralogists, and materials scientists, and engineers. Moreover, several specialized industries have already commercialized components based on PDCs, and the production and availability of the precursors used has dramatically increased over the past few years. In this feature article, we highlight the following scientific issues related to advanced PDCs research: (1) General synthesis procedures to produce silicon-based preceramic polymers. (2) Special microstructural features of PDCs. (3) Unusual materials properties of PDCs, that are related to their unique nanosized microstructure that makes preceramic polymers of great and topical interest to researchers across a wide spectrum of disciplines. (4) Processing strategies to fabricate ceramic components from preceramic polymers. (5) Discussion and presentation of several examples of possible real-life applications that take advantage of the special characteristics of preceramic polymers. Note: In the past, a wide range of specialized international symposia have been devoted to PDCs, in particular organized by the American Ceramic Society, the European Materials Society, and the Materials Research S...

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Section: Preceramic Polymer Synthesismentioning

confidence: 99%

Polymer‐Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

Colombo

Mera

Riedel

et al. 2010

Journal of the American Ceramic Society

1,554

582

View full text Add to dashboard Cite

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“…Vapor pressure osmometry (VPO) was measured in benzene solution at 40oC using a Corona 117 molecular weight apparatus. 1 H, 13 …”

Section: Measurementsmentioning

confidence: 99%

“…The cyclopolymerizations of diallylsilanes, 8 -10 dimethallylsilanes, 9 allyl(3-butenyl)silanes, 11 bis(3-butenyl)silanes, 11 triallylsilanes, 10 • 12 dipropargylsilanes, 13 and dimethyldivinyloxysilane 14 were carried out by radical, cationic, or coordination initiators, but anionic mechanisms could not be employed.…”

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confidence: 99%

Cyclopolymerization Behavior of Bis(dimethylvinylsilyl)methane

Suga

Oku

Takaki

1998

Polym J

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ABSTRACT:Anionic cyclopolymerization of bis(dimethylvinylsilyl)methane (BVSM) in hexane, which affords a polymer having six-membered rings as repeating cyclic units, is investigated. Low polymer yields in the polymerization of BVSM with n-butyllithium (n-BuLi) in the absence of N,N,N',N'-tetramethylethylenediamine (TMEDA) are attributed to cross-linking reactions and association of the propagating ends at -lO'C and elimination of lithium hydride from the propagating end at 40°C. Polymerization with n-BuLiiTMEDA is accompanied, though not frequently, by the abstraction of the methylene proton interposed by two silicon atoms, which forms an inactive anion. This abstraction is caused by the propagating end in the six-membered ring. At high monomer concentration, 0.5 moll-1 , cross-linking reaction is not negligible even in the presence of TMEDA. As initiators, n-, s-, t-BuLi are examined, and only s-BuLi/TMEDA is found to cause the proton abstraction from the methylene interposed by two silicon atoms. The effects of the initiator are explained by the nucleophilicity of BuLi and the steric hindrance in the abstraction. The effects of three amines on the polymerization arc evaluated. TMEDA is the most suitable for the cyclopolymerization of BVSM among them.

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“…Unsaturated polycarbosilanes represent a special class of hybrid polymers with silicon being bonded to π-conjugated building blocks, such as phenylene, ethenylene, or diethylene [ 36 , 37 , 38 , 39 , 40 ]. The synthesis of these materials has been achieved by using coupling reactions [ 38 , 41 ] thermal cyclopolymerization [ 42 , 43 ] and a variety of ring-opening polymerization reactions including anionic [ 44 , 45 , 46 , 47 ], thermolytic and catalytic coordination techniques [ 48 ], each of them with some limitations. A novel approach for the synthesis of unsaturated polycarbosilanes involves the catalytic acyclic diene metathesis (ADMET) reaction of unsaturated oligosilanes in the presence of a ruthenium carbene complex RuCl 2 (PCy 3 ) 2 (=CHPh) (Grubbs catalyst) [ 49 ].…”

Section: Preceramic Polymersmentioning

confidence: 99%

Ceramic Nanocomposites from Tailor-Made Preceramic Polymers

et al. 2015

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The present Review addresses current developments related to polymer-derived ceramic nanocomposites (PDC-NCs). Different classes of preceramic polymers are briefly introduced and their conversion into ceramic materials with adjustable phase compositions and microstructures is presented. Emphasis is set on discussing the intimate relationship between the chemistry and structural architecture of the precursor and the structural features and properties of the resulting ceramic nanocomposites. Various structural and functional properties of silicon-containing ceramic nanocomposites as well as different preparative strategies to achieve nano-scaled PDC-NC-based ordered structures are highlighted, based on selected ceramic nanocomposite systems. Furthermore, prospective applications of the PDC-NCs such as high-temperature stable materials for thermal protection systems, membranes for hot gas separation purposes, materials for heterogeneous catalysis, nano-confinement materials for hydrogen storage applications as well as anode materials for secondary ion batteries are introduced and discussed in detail.

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Cyclopolymerization of dipropargylsilanes by transition-metal catalysts

Cited by 41 publications

References 0 publications

Polymer‐Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

Polymer‐Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

Cyclopolymerization Behavior of Bis(dimethylvinylsilyl)methane

Ceramic Nanocomposites from Tailor-Made Preceramic Polymers

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