Chemical Properties
Colorless or yellowish transparent liquid
Uses
2,4,6,8-Tetramethylcyclotetrasiloxane can occur addition reaction with unsaturated alkenes, so it’s utilized widely to synthesize variety functional reactive silicone fluids which is used to form silicone block copolymer, or used as crosslinker of vinyl addition silicone rubber.
Tetramethyl-cyclotetrasiloxane is a good impregnant of photoelectric material. It is used to manufacture of modified siloxane with defined hydrogen content and chain quantity. It is also used in production of silicone polymers and acts as a precursor for the deposition of polysiloxane, cyclic siloxane, silicon dioxide, oxycarbide thin films with low dielectric constant for microelectronics and semiconductors.
General Description
Atomic number of base material: 14 Silicon
Flammability and Explosibility
Flammable
Synthesis
The synthesis process of 2,4,6,8-Tetramethylcyclotetrasiloxane is as follows. A 1-L four-necked flask equipped with a thermometer, stirrer, column packed with cylindrical glass of about 1x1 mm to a height of 500 mm, water-cooled condenser, outlet tube, and distillate receiver was connected to a vacuum pump. To the flask were fed 100 g of trimethylsiloxy end-capped dimethylpolysiloxane having a viscosity of 10,000 centistokes at 25°C and 1.0 g of the catalyst (i) synthesized above, after which agitation was commenced. While the flask interior was kept under a reduced pressure of 50 mmHg, the flask was heated at 250-260°C using a mantle heater. A fraction distilled out for 14 hours was collected (45 g). The residue (31 g) was a clear liquid. yeild= 52%
Toxics Screening Level
The initial threshold screening level (ITSL) for 2,4,6,8-tetramethylcyclotetrasiloxane is
100 μg/m3(annual).
