Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone Resins

Structural characterization of a polymethylsilsesquioxane (PMSQ) and a DT-type methyl silicone resin (MeDT) has been carried out by various instrumental analyses including GPC, NMR, gas chromatography, and gas chromatography-mass spectrometry. Although the PMSQ had a Mw around 5000, the resin contai...

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Main Authors: Maki Itoh, Fukuyo Oka, Michitaka Suto, Simon D. Cook, Norbert Auner
Format: Article
Language:English
Published: Wiley 2012-01-01
Series:International Journal of Polymer Science
Online Access:http://dx.doi.org/10.1155/2012/526795
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author Maki Itoh
Fukuyo Oka
Michitaka Suto
Simon D. Cook
Norbert Auner
author_facet Maki Itoh
Fukuyo Oka
Michitaka Suto
Simon D. Cook
Norbert Auner
author_sort Maki Itoh
collection DOAJ
description Structural characterization of a polymethylsilsesquioxane (PMSQ) and a DT-type methyl silicone resin (MeDT) has been carried out by various instrumental analyses including GPC, NMR, gas chromatography, and gas chromatography-mass spectrometry. Although the PMSQ had a Mw around 5000, the resin contained a significant amount of low molecular weight species consisting of T2 [MeSi(OH)O2/2] and T3 [MeSiO3/2] units, ranging from to including many isomers. One isomer of was isolated of which structure was determined as a cage structure. The species are supposed to consist mainly of cyclotetra- and cyclopentasiloxanes, but presence of strained rings such as cyclotrisiloxane rings also was suggested. In MeDT, species in which the T2 units in the molecules from PMSQ is replaced with D2 [Me2SiO2/2] were found, for example, , suggesting that general silicone resins consist of similar structures as silsesquioxanes. The Mark-Houwink exponent for these methyl resins was ~0.3, indicating the molecular shape to be compact. Investigation on the formation chemistry of the cubic octamers indicates that siloxane bond rearrangement is an important mechanism in the molecule build-up process.
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spelling doaj-art-76a2c889d2194c608290040327f71bf22025-08-20T02:07:16ZengWileyInternational Journal of Polymer Science1687-94221687-94302012-01-01201210.1155/2012/526795526795Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone ResinsMaki Itoh0Fukuyo Oka1Michitaka Suto2Simon D. Cook3Norbert Auner4Electronics Solutions S&T, Dow Corning Toray Co., Ltd., 2-2 Chigusa-Kaigan, Chiba Ichihara 299-0108, JapanElectronics Solutions S&T, Dow Corning Toray Co., Ltd., 2-2 Chigusa-Kaigan, Chiba Ichihara 299-0108, JapanElectronics Solutions S&T, Dow Corning Toray Co., Ltd., 2-2 Chigusa-Kaigan, Chiba Ichihara 299-0108, JapanAnalytical Sciences, Dow Corning Corporation, 2200 W. Salzburg Road, Midland, MI 48686-0994, USAInstitute for Inorganic and Analytical Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, GermanyStructural characterization of a polymethylsilsesquioxane (PMSQ) and a DT-type methyl silicone resin (MeDT) has been carried out by various instrumental analyses including GPC, NMR, gas chromatography, and gas chromatography-mass spectrometry. Although the PMSQ had a Mw around 5000, the resin contained a significant amount of low molecular weight species consisting of T2 [MeSi(OH)O2/2] and T3 [MeSiO3/2] units, ranging from to including many isomers. One isomer of was isolated of which structure was determined as a cage structure. The species are supposed to consist mainly of cyclotetra- and cyclopentasiloxanes, but presence of strained rings such as cyclotrisiloxane rings also was suggested. In MeDT, species in which the T2 units in the molecules from PMSQ is replaced with D2 [Me2SiO2/2] were found, for example, , suggesting that general silicone resins consist of similar structures as silsesquioxanes. The Mark-Houwink exponent for these methyl resins was ~0.3, indicating the molecular shape to be compact. Investigation on the formation chemistry of the cubic octamers indicates that siloxane bond rearrangement is an important mechanism in the molecule build-up process.http://dx.doi.org/10.1155/2012/526795
spellingShingle Maki Itoh
Fukuyo Oka
Michitaka Suto
Simon D. Cook
Norbert Auner
Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone Resins
International Journal of Polymer Science
title Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone Resins
title_full Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone Resins
title_fullStr Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone Resins
title_full_unstemmed Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone Resins
title_short Characterization and Some Insights into the Reaction Chemistry of Polymethylsilsesquioxane or Methyl Silicone Resins
title_sort characterization and some insights into the reaction chemistry of polymethylsilsesquioxane or methyl silicone resins
url http://dx.doi.org/10.1155/2012/526795
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