Master Bond Launches Toughened Epoxy for Sealing Applications

Master Bond has launched Master Bond Supreme 121AOND, a toughened epoxy system for bonding and sealing applications. It is a two-component heat-curing system with a thixotropic, paste-like consistency.

Master Bond Supreme 121AOND is chemically resistant and offers a high glass transition temperature (Tg) of 200-210°C. It meets NASA's low outgassing specifications in ASTM E595 testing.

The epoxy offers reliable electrical insulation performance with a volume resistivity of over 1014 ohm-cm at 75°F. It has high bond strength with a room temperature tensile strength of 6,000-7,000 psi and a tensile modulus of 750,000-850,000 psi.

Master Bond Supreme 121AOND maintains its strength even at elevated temperatures, with a tensile modulus of 650,000-750,000 psi at 300°F. Its thermal conductivity is 4-5 BTU•in/(ft²•hr•°F) [0.58-0.72 W/(m•K)], providing a wide service temperature range from -80°F to +550°F [-62°C to 288°C].

Master Bond Supreme 121AOND cures at elevated temperatures and has a pot life of 2-3 days. A typical cure schedule is 1-2 hours at 200-210°F, followed by 3-4 hours at 250°F, and then 4-6 hours at 300°F.

An additional post cure of 2-4 hours at 350-400°F will further enhance the product. Despite the short cure time, the key benefit offered by this system is that it maintains high structural strength even at elevated temperatures. This system bonds well to a variety of substrates, including glass, fiber, metal, ceramic, rubber, and plastic.