Methyl Hydrogen Silicone Oil

Synonym: Methyl Hydrogen Silicone Fluid Polymethylhydrosiloxane PMHS

Methyl Hydrogen Silicone Oil is a highly effective, anhydrous silicone based on polymethylhydrogensiloxane. In addition to the properties of dimethyl silicone oil, the product also has active SI-H bonds in its molecular structure and can participate in various chemical reactions. Under the action of metal catalyst, it can cross-link at appropriate temperature and form a waterproof film on the surface of various substrates. The fluid is little change in physical properties over a wide temperature range. Its heat-resistant than dimethyl silicone oil, but its water-repellent moisture-proof and anti-sticking properties such as dimethyl silicone oil than good.

Chemical Properties

Cas No.: 63148-57-2

Molecular Formula : (CH3)3SiO[SiO (CH3)H]n-Si(CH3)3 

Appearance:Colorless clear oily liquid

Hydrogen Content (%):1.58-1.60

Viscosity (25℃,mm2/s):20-30

Density@ 25°C: 0.96~1.02g/cm3

Volatile Content:(150°,3H) ) ≤3%

Flash Point: ≥160°C

Acid Value (HCL,μg/g): ≤5


Production Process

In the production process of methyl hydrogen silicone fluid, the catalyst decomposes to produce pungent gas, which is partially mixed in the system, making the silicone oil smelly and its application restricted. Therefore, in the process of methyl silicone oil production, take measures to eliminate odor.

The production process of methyl hydrogen silicone fluid is carried out in a reaction kettle. The whole production process includes copolymerization process, boiling process, heat preservation process and cooling process,etc. During all process, low boiling gas is generated. After the condensed by condenser (circulating water, the condensation temperature is room temperature) , guide the condensate gas to the activated carbon absorption device for treatment and then it is discharged at an altitude of 15m through the exhaust cylinder.


  1. Excellent water repellency.
  2. Low surface tension.
  3. Little change in physical properties over a wide temperature range.
  4. The fluids are thermally stable at 150° C for extended time intervals.
  5. Low toxicity.
  6. Compatible with most plastics and surface coatings.
  7. Good releasability.
  8. Can be diluted in solvents, for better dispersion.
  9. Effective at very low concentration.

How To

Methyl Hydrogen Silicone Fluid is usually applied from dilute solution. Solutions are prepared by diluting solvents like acetone or methyl ethyl ketone and stirring the mixture gently until it uniforms. The extent of dilution will depends on the surface to be treated and surface properties desired.


Methyl hydrogen silicone fluid is the earliest organosilicon polymer used commercially. it is widely used in electrical, mechanical, coating, medical and other sectors of the national economy because of its excellent oxidation resistance, shear resistance, low surface tension, hydrophobic, defoaming and other properties.

Typical uses are as follows:

  1. Used as the cross linker for addition type silicone rubber series.
  2. Used as the basic material and a fundamental intermediate to synthesize some modified silicone oil including polyether modified silicone oil.
  3. It is used as waterproofing additive in the production process of gypsum board.
  4. Treatment for powders and granular materials to make them water repellent and   free flowing, and to reduce caking.
  5. Oily foundation makeup in the thinning agent used and lubricants, anti-corrosion anti-viscosity.
  6. Antiadhesion isolating, releasing and cross-linking agents for paper.
  7. Waterproof agent and softener for fiber glass.
  8. With the important natural and synthetic fabrics, silk, leather waterproofing.


May evolve hydrogen gas in presence of catalyst and heat, when comes in contact with "HO-R" where R = alkyl , aryl , H , metal.

Avoid contact with acidic, basic and oxidizing materials. Contact with these materials can cause the liberation of large amounts of flammable (hydrogen) gas. Do not reuse containers unless drained and flushed with clean neutral solvent.