- Possibilities of using trimethylpentaphenyltrisiloxane as coolant for removing low-potential heat
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The resistance of commercial trimethylpentaphenyltrisiloxane to heat and to thermal oxidation was studied. The limits of its use as coolant in systems for removing low-potential heat were determined. Instrumental methods were developed and tested for moni
- Lebedev,Sheludyakov,Storozhenko,Gurskii,Tsapko, Yu. V.,Yasnev,Egorov,Osetrova
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- Diffusion pump oil synthesis method
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The invention relates to the chemical industry field, particularly to a diffusion pump oil synthesis method, which specifically comprises: (1) carrying out a hydrolysis reaction on methyl triethoxysilane to obtain 1,3-dimethyl-1,1,3,3-tetraethoxydisiloxane (short for compound B); (2) under a strong alkali condition, carrying out balanced telomerization on the compound B and a dimethyl ring body or methylphenyl ring body to obtain a compound D; (3) carrying out a sodium condensation reaction on the compound D, chlorobenzene and sodium to obtain the diffusion pump oil. According to the present invention, the reaction order is re-combined, and the method has advantages of low energy consumption and environmentally friendly process compared to the method in the prior art.
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Paragraph 0092; 0093
(2017/03/08)
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- Production of methylphenyltrisiloxane
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A process of producing a methylphenyltrisiloxane having the following general formula: STR1 wherein R1 and R2 may be the same or different and are each a methyl or phenyl group, the process comprising the step of reacting: (A) methyldiphenylsilanol, with (B) a silazane compound having a diorganosilazane unit having the following formula: STR2 wherein R1 and R2 are as defined above. According to the process, colorless and odorless methylphenyltrisiloxanes can be obtained easily, safely and economically, without any special deodorizing or decoloring step.
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- Process for the preparation of alkyl and aryl substituted oligosiloxanes suitable for use as diffusion pump oils
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An improved process for preparing 1,3-dialkyl-1,1,3,3-tetraryldisiloxanes and 1,3,5-trialkyl-1,1,3,5,5-pentaaryltrisiloxanes is disclosed. The process utilizes an aryl Grignard reagent to affect displacement of alkoxy, preferably methoxy, groups in the corresponding alkyl-alkoxy substituted di-, and trisiloxanes. Alternatively, partial replacement of the alkoxy groups in an alkyltrialkoxysilane with aryl groups in a Grignard reaction, and subsequent hydrolyis of the remaining alkoxy groups yield the above-noted desired compounds.
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