کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1324196 | 977327 | 2010 | 7 صفحه PDF | دانلود رایگان |
Highly regulated ladder-structured polymethylsilsesquioxanes soluble in solvents with high molecular weight were synthesized from sila-functionalized tetramethylcyclotetrasiloxanes [MeSiXO]4 (X = H, OEt, NCO) by the dehydrogenative condensation of [MeSiHO]4 with water in the presence of N,N-diethylhydroxylamine or the hydrolytic polycondensation of [MeSiXO]4 (X = OEt, NCO). Formation of a siloxane-ladder structure was confirmed based on the appearance of two absorption bands and a signal due to Si–O–Si linkage in the infrared spectra and a silsesquioxane unit in 29Si nuclear magnetic resonance spectra, respectively. The narrow half-peak width of the 29Si nuclear magnetic resonance spectra suggested the formation of a highly regulated ladder structure for polymethylsilsesquioxanes.
Ladder polymethylsilsesquioxanes (PMSQ-X) were synthesized by the polycondensation of [MeSiXO]4 (X = H, OEt, NCO). Infrared spectra, 29Si nuclear magnetic resonance, and size exclusion chromatography supports that PMSQ-NCO has a highly regulated ladder structure, or a random-coil conformation, with less defects in the siloxane framework.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 695, Issue 9, 1 May 2010, Pages 1363–1369