Two component epoxy compound for high performance applications

Key Features

  • Room temperature curing epoxy
  • Thermally conductive & electrically insulative
  • One to one mix ratio, by weight or volume
  • Impressive bond strength
  • Long working life
  • Low coefficient of thermal expansion

Product Description

Master Bond EP21AO is a two component, thermally conductive, electrically insulating epoxy adhesive, sealant, and coating with an excellent performance profile and convenient processing. It is very easy to use with a very forgiving one to one mix ratio by weight or volume. It cures at ambient temperatures or more rapidly at elevated temperatures with the optimum schedule being overnight at room temperature followed by a few hours at 150-200°F. Its most prominent feature is its superior thermal conductivity yet maintaining superior electrical insulation values. EP21AO will bond well to a wide variety of substrates, including metals, composites, ceramics, glass, rubbers and plastics. It has very good bond strength along with effective chemical resistance versus water, oil and fuels. Some other desirable properties include minimal shrinkage upon curing, a low coefficient of thermal expansion, superlative dimensional stability, top notch compressive strength and a high modulus of elasticity. The service temperature range is -60°F to +250°F. The color of Part A is gray and Part B is off-white. EP21AO has a resounding combination of properties where first rate heat transfer and highly reliable electrical insulation properties are needed, particularly in aerospace, electronic and specialty OEM type applications.

Product Advantages

  • Convenient mixing: non-critical one to one mix ratio by weight or volume; smooth flowing
  • Versatile cure schedules: ambient temperature cures or fast elevated temperature cures as required
  • High bonding strength to a wide variety of substrates
  • Low coefficient of expansion, very little shrinkage, superb dimensional stability
  • Outstanding thermal conductivity
  • Excellent electrical insulation properties




EP21AO is available is various sizes and units to accommodate customer's needs.

Request Information