Two part toughened epoxy for bonding, sealing and encapsulation features good thermal conductivity

Key Features

  • Paste consistency
  • High temperature resistance
  • Exceptionally long open time
  • Passes NASA low outgassing

Product Description

Master Bond Supreme 121AOND is a thermally conductive epoxy for bonding, sealing and encapsulation. The mix ratio is 100:80 by weight. This system has a very long open time of 2-3 days and after mixing, it is a paste. Supreme 121AOND requires oven curing. A typical cure schedule would be 1-2 hours at 200-210°F followed by 3-4 hours at 250°F and then 4-6 hours at 300°F. Additional post curing at 350°F for 2-4 hours will further enhance product properties. Supreme 121AOND combines a high glass transition temperature along with an element of toughness, making it less rigid than typical higher temperature resistant epoxies.

Supreme 121AOND bonds to a wide variety of substrates including metals, composites, glass, and many rubbers and plastics. It adheres especially well to glass, fibers and ceramics. This system can withstand thermal cycling and mechanical stresses. Its physical strength profile is strong and steadfast, particularly its tensile modulus. It is a reliable thermal conductor while retaining excellent insulation properties. Supreme 121AOND has good resistance to chemicals including water, oils, fuels, acids and bases. The color of Part A is black and Part B is dark brown. Its service temperature range is -80°F to +550°F. It should be noted that Supreme 121AOND is particularly well suited for bonding and sealing applications. It should be considered in demanding aerospace, electronic, opto-electronic and specialty OEM type applications where this product profile is needed.

Product Advantages

  • Paste consistency with a long working life
  • Thermally conductive, electrically insulative
  • Superior physical strength properties
  • High glass transition temperature
  • Has an element of toughness
  • Combines exceptionally low shrinkage and high dimensional stability

Industrial Certifications

ASTM E595 Compliant

Meets EU Directive 2015/863




Supreme 121AOND is available is various sizes and units to accommodate customer's needs.

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