Master Bond MasterSil 157 is a two component, lower viscosity silicone compound for high performance potting and encapsulation. It is an addition cured system and does not require exposure to air for complete cross-linking. It has a ten to one mix ratio by weight and will not outgas while curing. The system is 100% solids and contains no solvents. Curing is straightforward and relatively simple; 12-24 hours at ambient temperatures followed by 3-5 hours at 150-200°F. MasterSil 157 is highly flexible, optically clear and retains these properties over the service temperature range of -175°F to +500°F. It is capable of withstanding the most rigorous thermal cycling and shock. Its water resistance is quite good. These properties enable MasterSil 157 to be used in applications involving sensitive optical and electrical components. Some other specialty uses include encapsulating LEDs, optical fiber cladding and potting connectors. Also noteworthy are its low index of refraction and its ability to transmit light very well from 220-2,500 nanometers. MasterSil 157 has prominence in optical, opto-electronic, specialty OEM and related applications where the attributes mentioned above, particularly low temperature serviceability, are desirable.
Product Advantages
Addition cured; no by-products released during cure; does not require air for curing
Low exotherm; very long pot life
Can cure in thicknesses beyond 1 inch
Very low shrinkage upon cure
Excellent optical clarity and transmission properties
Superior electrical insulation properties; highly resistant to water
