Trimethylsilylation of the hydrolysed and polycondensed products of methyltriethoxysilane

doi:10.1016/S0021-9673(00)90041-4

Journal of Chromatography A

Volume 410, 1987, Pages 137-143

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Abstract

Trimethylsilylation was applied to the hydrolysed and polycondensed products of methyltriethoxysilane in an aqueous solution containing sodium ions. Five trimethylsilylated derivatives of methylsilsesquioxanes present in the solution were detected by gas chromatography and identified by combined gas chromatograph-mass spectrometry.

References (19)

H. Scholze
J. Non-Cryst. Solids
(1985)
H. Schmidt
J. Non-Cryst. Solids
(1985)
S. Sakka et al.
J. Non-Cryst. Solids
(1986)
G. Eglinton et al.
Chem. Geol.
(1974)
F.F.H. Wu et al.
J. Chromatogr.
(1970)
G. Garzó et al.
J. Chromatogr.
(1978)
G. Garzó et al.
J. Chromatogr.
(1976)
C.W. Lentz
Inorg. Chem.
(1964)
B.R. Currell et al.
J. Macromol. Sci., Chem.
(1981)

There are more references available in the full text version of this article.

Cited by (9)

Polymerization reactions in methyltriethoxysilane studied through 29Si NMR with polarization transfer
1998, Journal of Non-Crystalline Solids
²⁹Si nuclear magnetic resonance (NMR) spectroscopy was used to identify and characterize the alkoxysilane polymers formed in the early stages of the hydrolysis and condensation reactions of methyltriethoxysilane (MTES) dissolved in ethanol. The distortionless enhancement by polarization transfer (DEPT) experiments were tuned for optimum sensitivity, quantitative information and also used as editing methods for ²⁹Si spectra of various oligomers. The structures of polymers were identified, including various linear oligomers up to tetramers and cyclic species with three and four silicon atoms. The proportion of cyclics and cagelike structures is more important with an excess of water. It is shown that the hydrolysis ratio and the pH affect the hydrolysis rate of the species formed.
29Si-NMR study of hydrolysis and initial polycondensation processes of organoalkoxysilanes. II. Methyltriethoxysilane
1994, Journal of Non-Crystalline Solids
The hydrolysis and initial polycondensation processes of methyltriethoxysilane (MTES) have been investigated by high-resolution ²⁹Si-nuclear magnetic resonance spectroscopy (²⁹Si-NMR). MTES was hydrolyzed in the system with MTES:ethyl alcohol:water:HCL = 1:4:x:y; x = 1, 2, 3, 6; y = 1 × 10⁻⁴, 1 × 10⁻². Signals due to end and middle groups of polysiloxanes formed sub-regions on the basis of the number of hydroxyl groups attached to silicon, and the sub-region for silicon possessing more hydroxyl groups was observed at a lower field. Based on signal intensities, the signals due to the dimers (Me(HO)₂SiOSi(OH)₂Me and Me(HO)₂SiOSi(OH)OEt)Me) and the trimer (Me(HO)₂SiOSiMe(HO)OSi(OH)₂Me) (MeCH₃, EtC₂H₅) were identified.
Polysiloxane formation from a tetraethoxysilane-ethyl alcohol-oxalic acid system
1992, Journal of Non-Crystalline Solids
Polysiloxane formation in a tetraethoxysilane (TEOS)-ethyl alcohol (EtOD(H))-oxalic acid (OA) system without the addition of water was investigated by ²⁹Si nuclear magnetic resonance spectroscopy (²⁹Si-NMR). In the system with TEOS:EtOD(H):OA = 1:6:1, considerable amounts of linear oligosiloxanes possessing only ethoxy groups formed, and (EtO)₃SiOSi(OEt)₃, (EtO)₃SiOSi(OEt)₂OSi(OEt)₃, and (EtO)₃Si(OSi(OEt)₂)₂OSi(OEt)₃ were identified. When the amount of OA increased to TEOS:EtOD(H):OA = 1:6:2, the polymerization rate increased considerably. The observed Si-species scarcely possessed hydroxyls, suggesting unique siloxane formation in this system.
Exchange of Si(O-)<inf>4</inf> units in the cubic octameric silicate species Si<inf>8</inf>O<inf>20</inf>8- by MeSi(O-)<inf>3</inf>units
1991, Polyhedron
The structures and the distribution of species formed by adding methyltriethoxysilane or 1,3-dimethyltetramethoxydisiloxane to a tetramethylammonium silicate methanolic solution, where the cubic octameric silicate species is predominantly present, have been studied. Me_nSi₈O_20-n^(8-n)− (n = 1-3) species have been formed in the solutions, which have the double eight-membered (Si₄O₄) ring siloxane skeleton structure consisting of both Si(O⁻)₄ and MeSi(O⁻)₃ units, indicating that Si(O⁻)₄ units in the cubic octameric silicate anion can be displaced by MeSi(O⁻)₃ units.
The preparation of boron-doped silicon carbide powder by the carbothermal reduction of oxides derived from the hydrolyzed methyltriethoxysilane
1988, Journal of Non-Crystalline Solids
A precursor prepared from a methyltriethoxysilane ((CH₃)Si(OC₂H₅)₃, MTES)-B(OC₂H₅)₃-polyacrylonitrile (PAN) composition was used for the synthesis of boron-doped SiC by carbothermal reduction. Initially, MTES was hydrolyzed with HCl (MTES: H₂O: HCl = 1 : 1 : 0.01) for 1 h in a sealed vessel. The number-average molecular weight measurement and a NMR spectrum revealed that the species in the solution were mainly oligometric. With the addition of B(OC₂H₅)₃, no significant changes in the distribution of the Si containing species were detected. The mixing of the hydrolyzed solution with a PAN-dimethylsulfoxide solution led to a homogeneous solution. After the evaporation of the solvents and the subsequent heat treatment at 220° C, brown precursor powder was obtained. By the heat treatment at 1600° C in Ar, it was converted to boron-doped SiC powder.
Isomeric Silicones: Reactive Phenylsilsesquioxane-Based MT Resins and Comments Concerning the Structure of the Phenylsilsesquioxane Homopolymer
2022, Macromolecules

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Journal of Chromatography A

Abstract

References (19)

J. Non-Cryst. Solids

J. Non-Cryst. Solids

J. Non-Cryst. Solids

Chem. Geol.

J. Chromatogr.

J. Chromatogr.

J. Chromatogr.

Inorg. Chem.

J. Macromol. Sci., Chem.

Cited by (9)

Polymerization reactions in methyltriethoxysilane studied through <sup>29</sup>Si NMR with polarization transfer

<sup>29</sup>Si-NMR study of hydrolysis and initial polycondensation processes of organoalkoxysilanes. II. Methyltriethoxysilane

Polysiloxane formation from a tetraethoxysilane-ethyl alcohol-oxalic acid system

Exchange of Si(O<sup>-</sup>)<inf>4</inf> units in the cubic octameric silicate species Si<inf>8</inf>O<inf>20</inf><sup>8-</sup> by MeSi(O<sup>-</sup>)<inf>3</inf>units

The preparation of boron-doped silicon carbide powder by the carbothermal reduction of oxides derived from the hydrolyzed methyltriethoxysilane

Isomeric Silicones: Reactive Phenylsilsesquioxane-Based MT Resins and Comments Concerning the Structure of the Phenylsilsesquioxane Homopolymer