Pentamethyldisiloxane

CAS NO.：1438-82-0
Empirical Formula: C5H16OSi2
Molecular Weight: 148.35
MDL number: MFCD00053658
EINECS: 215-873-5
SAFETY DATA SHEET (SDS)
Update Date: 2025-08-18 19:12:29

What is Pentamethyldisiloxane?

The Uses of Pentamethyldisiloxane

Pentamethyldisiloxane, is an organosilicon compound used in synthesis of siloxane-polyether copolymer surfactants. Pentamethyldisiloxane can also be used as source of the trimethylsilyl functional group in organic synthesis.

The Uses of Pentamethyldisiloxane

Pentamethyldisiloxane is used in the synthesis of siloxane-polyether copolymer surfactants. It is also used as source of trimethylsilyl functional group in organic synthesis.

Synthesis

Synthesis_1438-82-0
Take prepared potassium trimethylsilanolate 1.12kg in 2L of anhydrous tetrahydrofuran, was added dropwise with stirring dimethylchlorosilane1kg, dropwise, room temperature reaction 1h, filtered, concentrated, extracted with ether, dried and concentrated to give a high purity of 98% or more of pentamethyl disiloxane 1.2kg.

Properties of Pentamethyldisiloxane

Boiling point:	86 °C (lit.)
Density	0.760 g/mL at 20 °C (lit.)
refractive index	n20/D 1.373
Flash point:	-9°C
form	clear liquid
Specific Gravity	0.758
color	Colorless to Almost colorless
Water Solubility	Not miscible or difficult to mix in water.
Sensitive	Moisture Sensitive
Hydrolytic Sensitivity	3: reacts with aqueous base
BRN	1734568
InChI	InChI=1S/C5H16OSi2/c1-7(2)6-8(3,4)5/h7H,1-5H3
EPA Substance Registry System	Disiloxane, pentamethyl- (1438-82-0)

Safety information for Pentamethyldisiloxane

Signal word	Danger
Pictogram(s)	Flame Flammables GHS02
GHS Hazard Statements	H225:Flammable liquids
Precautionary Statement Codes	P210:Keep away from heat/sparks/open flames/hot surfaces. — No smoking.