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

Key Features

  • Convenient handling
  • Flowable
  • High bond strength
  • Meets NASA low outgassing

Product Description

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.

Product Advantages

  • Convenient handling, 1:1 mix ratio by weight
  • High viscosity, flowable consistency
  • Very strong adhesive
  • Thermally conductive, electrically insulative
  • NASA low outgassing

Industrial Certifications

ASTM E595 Compliant

Meets EU Directive 2015/863



Double Barrel Cartridge

Gun Applicator


MasterSil 323AO-LO is available is various sizes and units to accommodate customer's needs.

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