16-10-2019 | Masterbond | Subs & Systems
Master Bond Supreme 121AO is a NASA low outgassing approved epoxy ideal for bonding, sealing and potting applications. Providing a high glass transition temperature of 200-210C, it resists temperatures of up to 550F. This system displays an element of toughness and is not as stiff as conventional epoxies that resist extreme temperatures.
The epoxy has a noteworthy strength profile with a tensile modulus of 750,000 to 850,000psi at room temperature and compressive strength of 26,000 to 28,000psi. Its thermal conductivity is 4-5BTU•in/(ft2•hr•F), and it is also electrically non-conductive. Shrinkage upon cure is especially low. This system not only resists thermal cycling and mechanical stresses but also withstands many chemicals, incorporating water, fuels, oils, acids and bases. The epoxy can be employed in aerospace, electronic, optoelectronic and OEM applications.
This two-part epoxy has a mix ratio of 100 to 80 by weight. The viscosity of the mixed compound is 10,000-25,000cps, making it easily pourable for potting and casting. It has a long working life after mixing of two-three days, for a 100g batch. The recommended cure schedule is one-two hours at 200F followed by three-four hours at 250F, and then four-six hours at 300F. Further post-curing at 350F for two-four hours will enhance product properties even further.
