Master Bond‘s 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 allows for the application of thin and thick sections, depending on the application.
MasterSil 323 is capable of withstanding rigorous thermal cycling and shock without cracking or exerting stress on components.
This new silicone offers excellent flexibility, with an elongation of 150 to 250% at room temperature. It has a Shore A hardness of 35-45 and a low-tensile modulus of 100 to 175 psi at 75°F for stress relief. It also has a low dielectric constant of 2.8 at 75° F, 1 MHz.
“MasterSil 323 is a specialty compound, which not only offers strain relief upon cure, but also provides decent bond strength to a variety of substrates — especially considering that it’s a silicone,” said senior product engineer, Rohit Ramnath. “The lap-shear strength for an aluminum to aluminum bond joint is around 200 to 250 psi at 75° F. Moreover, MasterSil 323 is optically clear in thinner sections and has a refractive index of 1.44 at 589 nm. It has a wide service temperature range of -65° to 400° F.”
The optimal cure schedule for MasterSil 323 is overnight at room temperature followed by two to four hours at 135 to 165° F. The material will fully cure without exposure to air or humidity. The working life of a mixed 100 gram batch is approximately two to three hours. It also has extremely low shrinkage upon curing.
MasterSil 323 is available for use in a half-pint, pint, quart, gallon kit containers, 30 cc syringe kits, and 50 cc double-barrel cartridges for gun dispensers. Its shelf life in original, unopened containers at 75° F is six months.
- Convenient handling
- Optically clear in thin sections
- Low to moderate viscosity
- Excellent strength properties