Master Bond EP21TPFL-1AO is an electrically insulative, two part epoxy polysulfide system with a thermal conductivity of 9-10 BTU•in/ft2•hr•°F [1.30-1.44 W/(m·K)]. As a polysulfide based system, it has very good chemical resistance, particularly to fuels, oils, hydraulic fluids and related compounds. This unusual blend of properties, enables EP21TPFL-1AO to be a candidate for a variety of bonding, sealing, coating and encapsulation applications in the electronic, aerospace, specialty OEM and related industries.With an elongation of 150-200%, EP21TPFL-1AO offers a high degree of flexibility and it can withstand intense thermal cycling and mechanical shock. This low viscosity system also has a hardness of 70-90 Shore A. The mix ratio is a forgiving two to three by weight or volume. Color coding facilitates mixing. Part A is black and Part B is off-white. Working life is a conveniently long 90-120 minutes at 75°F.
EP21TPFL-1AO fully cures at ambient temperatures and should not be heated. It has very good adhesion to metals, ceramics, composites, glass, and many rubbers and plastics. This compound is serviceable over the wide temperature range of -60°F to +250°F and has a 6 month shelf life in original, unopened containers. EP21TPFL-1AO is available for use in ½ pint, pint, quart, gallon or 5 gallon container kits.
