Silicone Encapsulation Compound HACKENSACK, N.J., Dec. 1, 2009 – Flexibility is important in the design of medical devices subjected to vibration, impact, shock and thermal cycling. Two-component, room temperature-curing Master Bond MasterSil 151 Med is a medical-grade casting, potting and encapsulation silicone formulated to withstand such exposures. With a low viscosity of 1500 centipoise, it provides complete fill in around complicated contours in complex configurations. It is a good electrical insulator with a volume resistivity of 1 × 1015 ohm cm and can handle service over the temperature range of -65 to 400 °F. MasterSil 151 Med cures with a refractive index of 1.43, making it well suited for use as a protective coating in optical and fiber optic applications. After the addition of a liquid curing agent, the base resin cures at ambient or, more quickly, at elevated temperatures to a tough, flexible and optically clear silicone rubber. Shrinkage upon cure is less than 0.1%. When cured, MasterSil 151 Med has a Shore A hardness of 45 and an elongation at break of 160%. Even though it has such high elasticity, its tensile strength is 880 lb per sq in. at 73 °F. Mix ratio is 10 to 1 by weight. The compound fully meets USP Class VI requirements for medical applications. It also can be used for potting and encapsulation of electronic components, electrical devices and various optical systems, and as a coating for solar cells and fiber optics.