Master Bond EP21AC is a two-part epoxy with non-halogenated filler formulated for applications where arc resistance and flame retardancy are required.

Was assigned PLC (performance level category) of 0 under UL746A High Amp Arc Ignition test. Is flame-retardant, per UL94HB standard for flammability testing. Is suitable for encapsulating, potting or coating. Has elongation of 10% to 20%. Is capable of resisting thermomechanical stresses. Is reportedly an excellent electrical insulator with a volume resistivity greater than 10¹⁴ohm-cm. Has dielectric constant of 4.7 at 75°F. Other properties include tensile strength of 5,000-6,000psi and tensile modulus of 300,000-350,000psi at 75°F. Is serviceable over temp. range of -60°C to +90°C; 1 to 1 mix ratio by weight; cures at room temp. or more rapidly with heat. Mixed viscosity is 30,000-50,000cps. Working life is 75-120 min. at room temp. Bonds well to metals, ceramics, composites and many plastics and rubbers.

Master Bond
masterbond.com