PM-50 Phenylmethyl Silicone Fluid

Product Description: PM-50 Silicone Fluid is a clear, colorless and odorless Phenylmethyl Silicone Oil with a viscosity of 50cSt @ 25°C. It replaces methyl groups found in conventional PDMS Silicone oils with Phenyl groups. In doing so, thermal stability and resistance to oxidation are significantly increased. PM-50 remains stable at 204°C (open to air) and 260°C (closed to air). The fluid is further characterized by its high flash point, high dielectric strength, stability at extreme pressures, excellent lubricity and inertness to virtually all substrates.

Chemical Name: Dimethyl, Phenylmethylsiloxane

CAS No: 63148-52-7

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Availability: 1‐gallon (3.7kg net wt.), 5‐gallon pail (18.5kg net wt.), 55‐gallon drum (200kg net wt.)

PM‐50 is a low phenyl content fluid with a viscosity of 50cSt @ 25°C. In comparison to conventional PDMS silicone oils, PM‐50 has much higher thermal stability and remains stable at temperatures > 200°C (open system). Unlike the higher phenyl content PM‐125 & PPM‐500, its viscosity remains pourable at low temperatures (low VTC=viscosity‐to‐temperature coefficient), which makes PM‐125 an excellent choice for laboratory baths and heat transfer systems that circulate and pump the fluid at low temperatures.

As a calibration fluid, PM‐50 Silicone Fluid is widely used in Flow Control, Temperature Control and Motion Control technologies. Again, its advantage over conventional oils is that it will not break down at high temperatures and it will not coagulate at high pressures. It is widely used for instruments, gauges, sensors, meters and devices that are subject to extreme temperatures and high pressures.

PM‐50 Silicone Fluid has a higher RI value (1.425) than conventional PDMS silicone. It an excellent RI index matching fluid and optical fluid for use in sensor /imaging / LED and Photonics technologies that require a higher RI value than conventional fluids.

Typical Product Data:

Viscosity @ 25°C Specific Gravity Viscosity Temp Coefficient Pour Point °C Flashpoint °C Ignition Temp °C Refractive Index Surface Tension
50cSt 0.985 0.655 -57°C 275°C 482°C 1.425 25.0

Dielectric Properties:

Electrical Strength Permittivity @ 100Hz Permittivity @ 1MHz Dissipation factor @ 100Hz Dissipation factor @ 1MHz Volume resistivity Dielectric Constant
13.8kV/mm 2.77 2.77 0.0003 0.00005 1x10hz 2.77

Thermal Properties:

Thermal Conductivity Specific Heat @ 100°C Coefficient of Expansion cc/cc/°C Gel Time, hours 250°C in Air
0.15 W/(m.K) 0.405 0.00096 220‐260 hrs.

Viscosity @ Temperature:

Temperature Viscosity
99°C 14cSt
38°C 38cSt
25°C 50cSt
-29°C 275cSt
-48°C 520cSt
-57°C 1,020cSt


  • High Flash Point
  • Formulated for stability at both low high temperature
  • Low viscosity change at temperature (low VTC): easy to pump and circulate the fluid at low temperature
  • High Refractive Index RI 1.425
  • High Dielectric Strength
  • Hydrophobic
  • Stable under high rates of pressure
  • Stable under high rates of shear
  • Excellent Lubricity

Applications Include:

  • High Temperature Laboratory Bath Fluid
  • Low Temperature Bath Fluid
  • High Temperature Heat Transfer Fluid
  • Low Temperature Heat Transfer Fluid
  • High Temperature Dielectric Fluid
  • High Temp /High Pressure Fluid
  • High Temperature Fluids for Flow Control Fluid
  • Refractive Index Matching Fluid
  • High RI Matching Fluids for LED and Optics
  • High Temp Silicone Lubricants for Plastic Parts
  • Silicone Lubricants for Rubber Parts
  • High Temperature Calibration Fluid
  • Fluid for Touch Screen Technology

Industries & Fields of Research include:R&D, Education, Defense, Oil & Gas Exploration, Energy, Aviation, Aerospace, Life Sciences, Renewable Energies, Turbine Technology, Wind Power Technology, Temperature Control Technologies, Geothermal, Solar Industry, Sensor Technology, Geosciences, Electronics, Environmental, Electrical Testing, Optics, LED, Photonics, MEMS Technology, Refractive Index Matching Digital Display Technology, Flow Control, Flow Meters, Deep Sea / Subsea Technologies, Dielectric Fluids for Wire & Cable, Deepwater, ROV Technologies, Laser Technology Research, Earth & Atmospheric Sciences, Seismic Research, Oceanography Research, Physical Sciences, Chemical Engineering, Mechanical Engineering, 3D Printing Technology, Plasma Research, LCD Technologies, Polymer Research, Computer Engineering Research, Robotics Research, Plastic Manufacturing, Rubber Manufacturing, Hydraulics, Nanotechnology Research, Geothermal, Fuel Cell Technology, Hydrophobic Coatings, Lighting Systems, Seismology, Aeronautics, Pipe & Tubing Systems, Printing Industry, Industrial Cleaning, Touch Screen Technology, Fiber Optics, Touch Monitor Technology, Touch Screen Technology, Temperature and Process Controllers

Environmental: Silicone Fluids are exempt from Federal VOC regulations, including California (CARB) and OTC regulations. They are HAP‐free and do not contribute to ozone‐depletion and global warming. In addition, they meet RoHS Compliancy.