Master Bond Polymer System EP121 is a new superior and cost effective two component epoxy resin system for electrical potting and encapsulation which combines high physical strength properties, remarkable thermal shock and heat resistance, inertness to water and chemicals with good electrical insulation characteristics. It has a service temperature range from -60°F to over 250°F. Adhesion to both metallic and nonmetallic substrates is excellent. Master Bond Polymer System EP121 offers the application convenience of a one-to-one non critical mix ratio for the two components plus flexible cure schedules so as to best meet specific processing requirements.

Master Bond Polymer System EP121 is supplied in the form of two liquid components each having a minimum stability of more than 9 months when stored at temperatures of around 75+5°F. It is readily prepared for potting or encapsulation by simple mixing of the two components in a one-to-one non critical mix ratio, weight or volume. Gel times and cure schedules depend upon temperature. A recommended gel time is 1 to 11 hours at 212-225°F. Full cure can be achieved by heating the gelled EP121 epoxy resin system for an additional 1-2 hours at 250°F. Post cures at higher temperatures e.g. 1-3 hours at 300°F are optional, their main benefit being an increase in the heat distortion temperature.