Master Bond (Hackensack, NJ) MasterSil 323 is a two component, addition cured system for bonding, sealing and potting applications. This product has a convenient to use 1:1 mix ratio, and can be packaged in double barrel cartridges for dispensing from a gun applicator. It can be applied in thin and thick sections. This silicone has excellent flexibility, with an elongation of 150-250% at room temperature, a Shore A hardness of 35-45 and a low tensile modulus of 100-175 psi at 75°F for stress relief. It is capable of withstanding rigorous thermal cycling and shock without cracking or exerting stress on components. Additionally, MasterSil 323 has a low dielectric constant of 2.8 at 75°F, 1 MHz.
The optimal cure schedule for MasterSil 323 is overnight at room temperature followed by 2-4 hours at 135-165°F. The material will fully cure without exposure to air or humidity.