- Studies on the synthesis and thermal properties of alkoxysilane-terminated organosilicone dendrimers
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Silicone core dendrimers bearing terminaldialkoxy andtrialkoxy silane groups were prepared in a three-step synthesis. Initially, the Si-H terminated multifunctional silicone dendrimer, i.e. tetrakis(dimethylsiloxy)silane, was prepared by the reaction of tetraethoxysilane and dimethylethoxysilane. Tetrakis(dimethylsiloxy)silane on reaction with allylglycidylether in the presence of Speier's catalystunderpressure (100 psi) yieldedepoxy- terminateddendrimerin veryhigh yield (95%).Theepoxy-terminated dendrimer was reacted with aminopropylalkoxysilanes to yield the next-generation dendrimer bearing dialkoxy and trialkoxy silane groups. The dendrimers were characterized by the usual physico-chemical techniques, i.e. elemental analysis, FT-IR, 1H, 13C and 29Si NMR. Thermal studies (Thermogravimetric analysis and Thermomechanical analysis) of the alkoxy terminated dendrimers and its cured products were also carried out. Copyright
- Saxena, Kanak,Bisaria,Saxena
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- Novel Polyorganosiloxanes And Use Thereof
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The invention relates to novel polyorganosiloxanes, methods for their preparation and their use, in particular as force and/or heat transmitting liquids, such as hydraulic liquids, and in cosmetic compositions.
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Page/Page column 5
(2012/03/10)
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- Preparation of branched siloxane
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By reacting a branched siloxane compound of formula (2) containing compounds of formula (1) as an impurity with a disiloxane compound of formula (3) in the presence of an acid compound, there is prepared a branched siloxane of formula (2) containing a reduced level of compounds of formula (1).R1?nSi(OSiR2?3)3-n(OR3)R1?nSi(OSiR2?3)4-nR2?3SiOSiR2?3 R1 is a monovalent hydrocarbon group, R2 and R3 are H or monovalent hydrocarbon groups, and n is 0 or 1.
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Page/Page column 16
(2010/02/10)
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- New route to permethylcyclosiloxanes
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A new method for preparing permethylcyclosiloxanes, based on reaction of 1,1,3,3-tetramethyldisiloxane with iodine (molar ratio 1:1) in inert organic solvents (alkanes, alkyl halides, benzene) is proposed. The products of the reaction react with ethoxytrimethylsilane and tetramethoxysilane in hexamethyldisiloxane to give respectively pentamethyldisiloxane and products of successive substitution of the methoxy groups in Si(OMe)4 by Me2SiHO. A probable scheme of their formation is discussed.
- Basenko,Klyba,Voronkov
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p. 1368 - 1370
(2007/10/03)
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- Liquid crystalline organosilicon compounds
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Non-crosslinked, branched liquid crystalline organosilicon compounds exhibit the general formula where at least one R represents a mesogenic (liquid crystal forming) group, the remaning R represent monovalent hydrocarbon or halohydrocarbon radicals, w represents an integer having a value of at least 1, x, y, and z individually represent an integer including zero, the sum of x and y is at least 1 and the sum of w, x, y, and z is from 4 to 50, inclusive.
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