Two component, biocompatible silicone compound for potting and encapsulation

Key Features

  • Meets USP Class VI specifications
  • Passes ISO 10993-5 for cytotoxicity
  • High flexibility
  • Optically clear
  • Electrically insulative
  • Low viscosity

Product Description

Master Bond MasterSil 151Med is a two component, low viscosity silicone compound for high performance potting and encapsulation. MasterSil 151Med is an addition cured system and does not require exposure to air for complete cross-linking. It has a convenient ten to one mix ratio by weight, and will not outgas while curing. It is 100% solids and contains no solvents. MasterSil 151Med has an exceptionally low viscosity enabling it to be highly desirable for potting and encapsulation. First and foremost, MasterSil 151Med, as is true with silicones in general, offers remarkable flexibility and high temperature resistance. It has superb electrical insulation properties. The system’s flexibility allows it to withstand severe thermal cycling and resist vibration and shock. MasterSil 151Med resists gamma radiation, EtO and various chemical sterilants. These properties enable this system to be well suited for medical applications involving optical and electrical components. It can also be used for encapsulating electronic circuitry, LEDs, optical fibers and other optical components in a wide array of medical devices. MasterSil 151Med is transparent and has a service temperature range of -65°F to +400°F. It fully passes USP Class VI testing for biocompatibility.

Product Advantages

  • Addition cured; no by-products released during cure; does not require air for curing
  • Low exotherm; very long pot life; low viscosity ideal for potting and encapsulation
  • Readily cures at ambient temperatures or faster cure at elevated temperatures
  • Can cure in thicknesses beyond 1 inch
  • Very low shrinkage upon cure
  • Excellent optical clarity and transmission properties
  • Meets USP Class VI specification
  • Superior electrical insulation

Industrial Certifications

ISO 10993-5 for Cytotoxicity

Meets EU Directive 2015/863

USP Class VI Medical





MasterSil 151Med is available is various sizes and units to accommodate customer's needs.

Case Studies

Master Bond MasterSil 151Med was utilized by researchers in an implantable device for electrical nerve stimulation.

In a post doctoral thesis utilizing specialized MRI hardware developed for sensitive in-vivo detection of sodium to investigate differences between healthy and malignant prostate tissue, MasterSil 151Med was cited as follows. “Multiple versions of the probe were designed and constructed before the final design was chosen. I coated all the probes with biocompatible sealant (MS151 MED, Masterbond, NJ), which acted as a fluid-resistant seal as well as an additional layer of heat and electrical insulation.”1

Master Bond MasterSil 151Med was used in research done by a scientist from Norwegian University of Science and Technology. Here is a quote from this work:

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