141-63-9Relevant articles and documents
One-Step Synthesis of Siloxanes from the Direct Process Disilane Residue
Neumeyer, Felix,Auner, Norbert
supporting information, p. 17165 - 17168 (2016/11/23)
The well-established Müller–Rochow Direct Process for the chloromethylsilane synthesis produces a disilane residue (DPR) consisting of compounds MenSi2Cl6?n(n=1–6) in thousands of tons annually. Technologically, much effort is made to retransfer the disilanes into monosilanes suitable for introduction into the siloxane production chain for increase in economic value. Here, we report on a single step reaction to directly form cyclic, linear, and cage-like siloxanes upon treatment of the DPR with a 5 m HCl in Et2O solution at about 120 °C for 60 h. For simplification of the Si?Si bond cleavage and aiming on product selectivity the grade of methylation at the silicon backbone is increased to n≥4. Moreover, the HCl/Et2O reagent is also suitable to produce siloxanes from the corresponding monosilanes under comparable conditions.
PROCESS FOR STABILIZATION OF SILOXANE COMPOUNDS
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Page 7, (2008/06/13)
A method for stabilizing silicone dry cleaning solvents containing impurities, comprising contacting the silicone solvent with an adsorbent, neutralizing agent or combination thereof to purify the solvent and prevent reequilibration and polymerization, and separating the silicone solvent.
Kinetics and mechanism of the reaction between oligosiloxanes and P-trichloro-N-dichlorophosphoryl monophosphazene (Cl3P=N-POCl2)
Meliani, Abdeslam,Vaugeois, Yann,Bali, Hamza,Mazzah, Ahmed,De Jaeger, Roger,Habimana, Jean
, p. 283 - 301 (2007/10/03)
31P NMR investigation has been made of the action of Cl3P=N-POCl2 (I) first on hexamethyldisiloxane (Me3Si)2O and then on oligosiloxanes Me3Si-(OSiMe2)n-OSiMe3 n = 2 and n=3. The reactions were carried out in bulk or in solution with molar ratios siloxane/(I) varying from 1 to 5. It was demonstrated that only the monosubstitution of a chlorine atom by the -(OSiMe2)n-OSiMe3 species n = 0, 2, 3 with elimination of trimethylchlorosilane occurred leading to the derivatives Cl2OP-N=PCl2O-(SiMe2-O)nSiMe 3 (II). For n=2, 3 the siloxane redistribution reactions were observed by 29Si NMR analysis. A two steps mechanism is proposed, consisting in a nucleophilic substitution, involving a tricoordinate phosphazenium intermediate, followed by the formation of an active ionic centre probably an oxonium ion, arising from the solvatation by the siloxane of this phosphazenium ion and /or of (II) leading to the redistribution reactions. The influences of the solvent, of trimethylchlorosilane, of the temperature, and of the addition of a protonated species (MDH) were investigated.
