18547-01-8

Basic information

• Product Name: cyclotetrasiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetrakis(1-methylethoxy)-
• CAS NO: 18547-01-8
• Molecular Formula: C₁₆H₄₀O₈Si₄
• Molecular Weight: 472.826
• Mol File: 18547-01-8.mol
• Article Data: 2

Chemical Properties

• Boiling Point: 335.551°C at 760 mmHg
• Flash Point: 144.744°C
• Density: 1.013g/cm³
• Vapor Pressure: 0mmHg at 25°C
• Refractive Index: 1.44
• CAS DataBase Reference: cyclotetrasiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetrakis(1-methylethoxy)-(CAS DataBase Reference)
• NIST Chemistry Reference: cyclotetrasiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetrakis(1-methylethoxy)-(18547-01-8)
• EPA Substance Registry System: cyclotetrasiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetrakis(1-methylethoxy)-(18547-01-8)

Safety Data

• Hazardous Substances Data: 18547-01-8(Hazardous Substances Data)

Upstream product

• 2370-88-9 2,4,6,8-tetramethylcyclotetrasiloxane 
• 67-63-0 isopropyl alcohol 
• 220289-05-4 1,3-diisocyanato-1,3-diisopropoxy-1,3-dimethyldisiloxane 
• 999-89-3 dichloro-isopropoxy-methyl-silane 

Relevant articles and documents

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Syntheses and properties of sila-functional oligosiloxanes - Linear and cyclic tetrasiloxanes with methyl and vinyl groups

The syntheses of the titled oligosiloxanes by controlled hydrolysis of the corresponding isocyanatosilanes under vapor phase or in THF (or THF/ether) were investigated. The vapor phase hydrolysis of RSi(NCO)3 (R = Me, Vinyl) with a water-1,4-dioxane vapor gave the disiloxanes [R(OCN)2Si]2O in yields of 85% (R = Me) and 90% (R = Vinyl). Further vapor phase hydrolysis of the disiloxanes provided the linear tetrasiloxanes NCO[SiR(NCO)O]3SiR(NCO)2 in yields of 71% (R = Me) and 69% (R = Vinyl). The cyclotetrasiloxanes [R(OCN)SiO]4 were synthesized in yields of 12% (R = Me) and 33% (R = Vinyl) or 24% (R = Me) and 58% (R = Vinyl) by hydrolysis of the disiloxanes or of the linear tetrasiloxanes in THF, respectively. On the other hand, the linear tetrasiloxanes OCN[SiR(OPri)O]3SiR-(OPri)(NCO) were obtained in yields of 50% (R = Me) and 56% (R = Vinyl) by hydrolysis of [R(OCN)(PriO)Si]2O prepared from RSi(OPri)(NCO)2 under mild conditions in THF/ether, while the cyclic tetrasiloxanes [R(PriO)SiO]4 were afforded in the yield of 61-62% by hydrolysis of the disiloxanes under more severe conditions in THF.