Master Bond 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 of this product 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. “This silicone is ideal for applications where low stress is required, since it is highly flexible across a wide service temperature range. It is capable of resisting aggressive thermal cycles and shocks,” says Rohit Ramnath, Senior Product Engineer.
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 6-12 hours for a 50 gram mass. This silicone product has an elongation between 100-150%, tensile strength of 400-700 psi and can cure beyond ¼ inch thick. It features a thermal conductivity of 1.30-1.59 W/(m•K), 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°F 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 gram, 50 gram and 100 gram 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.