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Stepwise synthesis of a Zr–C–Si main chain polymer precursor for ZrC/SiC/C composite ceramics
Novel polymers containing a refractory metal in the main chain are highly desired as ultra-high temperature ceramic precursors. Herein, a low oxidation state active species Cp(2)Zr(ii) with two semi-filled outer orbits was firstly obtained using Cp(2)ZrCl(2) with Mg. This active species of Cp(2)Zr(i...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society of Chemistry
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8979093/ https://www.ncbi.nlm.nih.gov/pubmed/35425217 http://dx.doi.org/10.1039/d1ra07783j |
Sumario: | Novel polymers containing a refractory metal in the main chain are highly desired as ultra-high temperature ceramic precursors. Herein, a low oxidation state active species Cp(2)Zr(ii) with two semi-filled outer orbits was firstly obtained using Cp(2)ZrCl(2) with Mg. This active species of Cp(2)Zr(ii) was subsequently copolymerized with (CH(3))(2)Si(CH(2)Cl)(2) to form a PZCS precursor with a Zr–C–Si main chain. The pathways of constructing the Zr–C–Si main chain were proposed based on the active species Cp(2)Zr(ii) polymerization combined with the auxiliary function of ·MgCl, quite different from the conventional understanding of using the Grignard reaction mechanism to explain the synthesis of metal-containing polymer precursors. The ceramic yield of the PZCS precursor at 900 °C is 43.9 wt%, and the ZrC/SiC/C composite preceramic powder was prepared by the pyrolysis of the PZCS precursor, which has important application prospects in ultra-high sonic aircraft and aero rocket engines. It is expected that this stepwise method of using refractory metal-containing active species to synthesize main-chain metallopolymers would provide significant guidance for preparing novel UHTCs precursors. |
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