MasterSil 151S is an addition curing two-part silicone system that may be used as an adhesive, sealant, coating or form-in-place gasketing material. A unique feature is that despite its silicone chemistry, it passes NASA low outgassing specifications. Also, it retains superior electrical conductivity with a volume resistivity of 0.004 ohm-cm at 75°F.
The mix ratio of MasterSil 151S is 100 to 5 by weight, and it cures with the addition of heat. Upon mixing, it retains its smooth, paste consistency, and has a long working life of 6 to 12 hours for a 50-gram mass. This silicone product has an elongation between 100 to 150%, tensile strength of 400 to 700 psi, and can cure beyond 1/4-in. thick. It features a thermal conductivity of 1.30 to 1.59 W/(mK), a coefficient of thermal expansion of 150-200 x 10-6 in/in/°C, and hardness of 80-90 Shore A. It is serviceable over the temperature range of -80 to +400°F.
This compound bonds well to a variety of substrates including metals, ceramics, composites, and many plastics and rubbers. It is available for use in 20, 50, and 100-g glass jars. The color of Part A is silver and Part B is clear. MasterSil 151S has a low linear shrinkage upon curing and is RoHS compliant.
