MasterSil 323AO-LO

Oct. 13, 2022

Two part thermally conductive, electrically insulating silicone for bonding and sealing

Key Features

Convenient handling
Flowable
High bond strength
Meets NASA low outgassing

Master Bond MasterSil 323AO-LO is a two component silicone for high performance bonding, sealing and gap filling. This high viscosity, flowable system has a forgiving 1:1 mix ratio by weight. It has a long open time of 2-3 hours for a 100 gram mass. Various cure schedules are noted in the chart below with the optimum being 12-24 hours at room temperature, followed by 3-5 hours at 125°F to 175°F. As an addition cured system, unlike a condensation cure, it does not require exposure to air for complete cross-linking. Also, it contains no solvents or diluents and has very low shrinkage upon curing.

MasterSil 323AO-LO bonds well to a wide variety of substrates such as glass, metals, ceramics, plastics and many rubbers, including silicones. Unlike many other two part silicones, MasterSil 323AO-LO exhibits very good bonding capabilities. The system is a reliable thermal conductor while retaining strong electrical isolation. It will resist the most aggressive types of thermal cycling and shock. It imparts almost no residual stress on substrates with different coefficients of expansion when it is thermally cycled. The color of both Parts A and B are white. The service temperature range spans between -65°F to +400°F. MasterSil 323AO-LO passes NASA low outgassing specifications. This product is a viable option in many optical, electronic and specialty OEM applications, where a low outgassing, thermally conductive, electrically insulating silicone would be required.