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Ideal for use in the aerospace, electronic, opto-electronic and speciality OEM industries, Master Bond MasterSil 323AO-LO is a two component silicone elastomer with a self-priming feature, designed for bonding, sealing and gap filling applications. 

Electrically insulating and thermally conductive, MasterSil 323AO-LO meets NASA low outgassing specifications with a thermal conductivity of 1.15 – 1.30 W/(m•K). It is highly flexible with a low tensile modulus of 500 psi – 700 psi, an elongation of 50% – 60%, and a hardness of 70 – 75 Shore A. 

This combination of properties enables it to withstand aggressive thermal cycling and mechanical shock. It also has a relatively high strength profile for a silicone with a tensile lap shear strength of 250 psi – 350 psi at room temperature and bonds well to a wide variety of substrates, including metals, composites, glass, ceramics, plastics, and other silicones, without imparting residual stress when heat cured. Serviceability is from -65°F to +400°F (-54°C to +204°C).

MasterSil 323AO-LO features a paste-like consistency, which allows it to be used as a gap filling material where minimum flow after application is desired. This formulation offers a variety of cure schedule options, with the optimum being overnight at room temperature followed by 3 – 5 hours at 125°F – 175°F (51.6°C – 79°C). It does not require exposure to air for complete cross-linking. The elastomer has an easy to use
1:1 mix ratio and is available for purchase in standard containers or gun applicator kits, making it convenient for manual or automated dispensing.