293-51-6

Usage

Uses

cyclotetrasiloxane is a silicone-based emollient.

InChI:InChI=1/H8O4Si4/c1-5-2-7-4-8-3-6-1/h5-8H2

Upstream product

• 7732-18-5 water 
• 4109-96-0 Dichlorosilane 
• 554-13-2 lithium carbonate 
• 743369-26-8 zinc(II) carbonate 

Relevant academic research and scientific papers

Process for the manufacture of hydrogen-rich cyclosiloxane

The present invention relates to a for controlled synthesis of hydrogen-rich cyclosiloxanes of the (H2SiO)n type. where n is an integer equal to or greater than 3, by reacting: a.) a halosilane of the H2SiX2 type where X=halogen withb.) a lithium salt, copper(II) salt or a salt of a metal from main group 2 or transition group 2 of the periodic table of the elements, or a mixture of these salts. The ring size is advantageously adjustable to n=3, 4, 5, 6 (especially n=4 to 6), such that larger rings are not formed. In a particularly advantageous embodiment of the process, for the selective preparation of cyclohexasiloxane (H2SiO)6, after the reaction, the solvent is at least partly removed and then solvent is added again.

Linear polysiloxanes from dichlorosilane

Polysiloxanes of type RR′R″SiO(SiH2O)nSiRR′R″ (R, R′, R″ = Me, Me, Me; Me, H, H; Et, Et, Et; Me, Me, H) have been prepared by three different methods: (1) reactions of ClSiH2O(SiH2O)nSiH2Cl with CH3MgBr, Me3SiOH, and Et3SiOH; (2) H2SO4-catalyzed equilibration of cyclic [H2SiO]n oligomers with Me3SiOSiMe3; (3) cohydrolysis of H2SiCl2 with Me3SiCl and Me2HSiCl using NaH2PO4/Na2HPO4-buffered media. Lower species, Me2RSiO(SiH2O)nSiMe2R (n = 1-3), were isolated and characterized (R = Me, H).

Cyclic polysiloxanes from the hydrolysis of dichlorosilane

The hydrolysis of H2SiCl2 in dichloromethane solution, either with a stoichiometric amount of water at -30 to -20°C or by slow, controlled addition of a slight excess of water at 0°C, results in the formation of siloxanes of type [H2SiO]n. In the volatile fraction oligomers with n from 4 up to 23 were found. Those with n = 4-6 were isolated by GC and characterized (1H and 29Si NMR, IR, n25D, mass spectroscopy). A brief study was made of the hydrolysis of MeSiHCl2 and Me2SiCl2 under comparable conditions.

Preparation of cyclotetrasiloxanes aliphatic chlorides and acyl chlorides

A method for preparing cyclotetrasiloxane, aliphatic chlorides and/or acyl chlorides from a chlorosilane and an acyloxy compound is disclosed. The chlorosilane and the acyloxy compound may be present as substantially equimolar amounts of separate compounds or they may be present in the same molecule in equimolar amounts. The reactants are merely heated sufficiently, with or without a soluble halide salt catalyst, to form the products. Advantageously this method can provide cyclotetrasiloxanes having water-sensitive radicals such as silicon-bonded chlorine atoms and/or silicon-bonded acyl chloride radicals.