Abrasion resistant, electrically insulative epoxy
Master Bond EP21NS two-part epoxy may be used for bonding, coating, sealing, and potting/encapsulating. Its nanosilica filler imparts dimensional stability and abrasion resistance. When measured according to ASTM D4060, standard test method for abrasion resistance, with CS-17 wheel for 1,000 cycles, EP21NS exhibits a very low weight loss of 25mg. This formulation is a reliable electrical insulation with a volume resistivity greater than 1015ohm-cm, an outstanding dielectric constant of 2.6 at 16.4GHz, and a dielectric strength of 450volts/mil at 75°F, for a 0.0125" thick specimen. It is serviceable over the temperature range of -80°F to 250°F.
This system has a long working life and good flow properties with a moderate mixed viscosity of 50,000cps to 90,000cps. The mix ratio of EP21NS is 1 to 1 by weight, and its optimal cure schedule is overnight at room temperature followed by 4 to 5 hours at 150°F. It features very low shrinkage upon curing, a low coefficient of thermal expansion of 30-to-35x10-6x in/in/°C and a compressive strength of 16,000psi to 18,000psi.
This compound bonds well to a variety of substrates including metals, composites, glass, ceramics, rubbers, and many plastics. EP21NS is resistant to water and salts. It is packaged in ounce kits, half-pint kits, pint kits, and quart kits. The color of Part A is translucent and Part B is amber. EP21NS does not contain solvents and is RoHS compliant.