EP21TDC-2LO Product Description

Two Component, Highly Flexiblized, Thermally Conductive, Electrically Insulating Epoxy Resin Compound for High Performance Bonding, Sealing, Coating and Encapsulation. Passes NASA Low Outgassing Test.

Master Bond Polymer System EP21TDC-2LO is a two component, highly flexible epoxy resin compound for high performance bonding, sealing, coating, and encapsulation. It is formulated to cure fully at room temperature or more quickly at elevated temperatures with an easy to use one to three mixing ratio by weight. EP21TDC-2LO has outstanding toughness and, unlike most flexibilized epoxies, it passes NASA low outgassing test criteria. The cured compound exhibits a high elongation (greater than 25%), truly exceptional for a thermally conductive epoxy. EP21TDC-2LO produces very little heat after mixing, which allows for a long working life. This epoxy resin compound exhibits good tensile shear and peel strength for bonding and sealing many different substrates including metals, glass, ceramics, vulcanized rubber and many plastics. The cured epoxy is an excellent electrical insulator with superior chemical resistance to water, fuels and many solvents. Most noteworthy is its ability to withstand thermal shock, thermal cycling and mechanical shock. It has a service temperature range of 4K to 250°F and has been successfully employed in a number of cryogenic applications. Master Bond EP21TDC-2LO is an exceptionally versatile system that offers the structural benefits of an epoxy, yet incorporates flexibility and very good thermal conductivity. It is widely used in the electronic, electro-optical and related industries. The color of Part A is white; Part B is off-white.

Product Advantages

  • Convenient mixing: non-critical one to three mix ratio by weight.
  • Easy application: product spreads evenly and smoothly; long working life.
  • NASA low outgassing approved.
  • Versatile cure schedules: ambient temperature cures or fast elevated temperature cures.
  • High peel strength and elongation.
  • Excellent flexibility; exceptional thermal shock and chemical resistance.
  • Superior bonding properties on similar and dissimilar substrates, superb impact resistance.
  • High thermal conductivity combined with good electrical insulation properties.
  • Cryogenically serviceable down to 4K.


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