High Temperature Dielectric Silicone Fluids

Chemical Name: Diphenyl-Dimethylsiloxane (DPDM-400) Phenylmethylsiloxane (PM-125)

CAS No: DPDM-400: 68083-14-7, PM-125: 63148-52-7

High Temperature Dielectric Silicone Fluids (25°C to 300°C) are clear, colorless and odorless phenyl-class silicone fluids. They are characterized by their high dielectric strength, high flash points, high thermal stability, high resistance to oxidation, low vapor pressure and compatibility with virtually all surfaces including metal, rubbers and plastics.

High Temperature Dielectric Silicone Fluids are Phenyl-class Silicone fluids that are formulated for use in a wide range of applications that require high dielectric strength, high flash points, high thermal stability, resistance to oxidation, long service-life

High Temperature Dielectric Silicone Fluidswill remain stable up to 300°C in a closed system (closed system) and 250°C (open system). They contain no heat-stabilizers or additives. These fluids are hydrophobic, clear, colorless, odorless, and inert to virtually all metals, plastics and rubbers.

High Temperature Dielectric Silicone Fluids have Dielectric Strength of 400 volts/mil

View Dielectric Properties of High Temperature Dielectric Silicone Fluids

High Temperature Dielectric Silicone Fluids have Thermal Conductivity values between 0.00032 to 0.00035 g/cal/cm/sec °C. The Specific Heat values are 0.35 cal/g °C for the DPDM-400 Heat Transfer Fluid. The Specific Heat value for the PM-125 is 1.418 kJ/kg K @ 0°C.

Unlike conventional silicone fluids, the viscosity of the High Temperature Silicone Heat Transfer Fluids will lower very quickly as soon as they are heated. This makes them excellent choices for systems that need to pump the fluid at high temperatures. Under heat, the High Temperature Dielectric Silicone Fluids will easily circulate and provide a consistent temperature.

Applications include: High Temp Dielectric fluids, high temperature dielectric coolants, dielectric fluid for heat transfer systems, calibration bath fluids for high temperature, high temperature silicone fluid for temperature control systems, Downhole (Borehole) Fluid

Product Data:

Property DPDM-400 PM-125
Chemical family Silicone Silicone
Chemical name Diphenyl-Dimethylsiloxane Phenylmethylsiloxane
CAS # 68083-14-7 63148-52-7
Appearance clear, colorless fluid clear, colorless fluid
Odorless Yes Yes
Hydrophobic Yes Yes
Viscosity @ 25°C 400cSt 125cSt
V.T.C. 0.82 0.76
Pour point -30°C -51°C
Flash point 315°C 315°C
Vapor pressure @ 25°C <1mmHg <1mmHg
Thermal conductivity g/cal/cm/sec °C 0.00032 0.00035
Specific heat @ 25°C J/g °C 0.35 1.498 kj/kg K
Thermal expansion cc/cc/°C 0.00073 0.00075
Service temperature 25°C to 300°C 25°C to 300°C


  • Clear, colorless, odorless fluids & inert fluids
  • Long service life @ recommended service temperatures
  • Low viscosity: will not put strain on pumps.
  • High Dielectric Strength
  • High Flash points
  • High Thermal Stability
  • Thermal conductivity: 0.00032 to 0.00035 g/cal/cm/sec °C
  • Low vapor pressure
  • High Resistance to oxidation
  • Exhibit significantly less viscosity change than petroleum based oils.
  • Formulated from 100% synthetic sources.
  • Long service life when used for recommended temperature ranges.
  • Inert to virtually all bath instrumentation and plastics
  • Environmentally friendly: VOC Exempt & HAP Free
  • Hydrophobic- will not absorb water