SILTRUST™ RTV681-LV – Meeting the Demands of Next-Gen Space Exploration

Since the beginning of mankind’s journey into space, Momentive has provided materials that make not only flight but space travel possible. Their GE Silicones were used in the sole of the first boot to imprint on the surface of the moon, with their silicone products enabling those pioneering the reinvention of the spacecraft today.

Leveraging decades of silicone rubber development, Momentive were able create RTV681-LV, a thermal control coating, that unlike other existing thermal control coatings, remains flexible after curing at extended temperatures.

SILTRUST™ RTV681-LV – Thermal Control Coating

Developed for long term durability in harsh environmental conditions, SILTRUST™ RTV681-LV is a white, highly reflective thermal control coating. To help meet the demands of the next generations of space exploration, this product has been designed to be easy to use, fast curing and with a flexible coating.

To meet the rate of demand of today’s space component manufacturing industry, RTV681 needed to be quick curing. Adding a two-part silicone curing system, allowed for a rapid 1hr cure, with heat or room temperature curing also being possible.

In addition to the fast curing, this silicone also has options for how it can be applied. It can be skived without dilution and can also be diluted for roll or spray application techniques.

To tackle the requirement of the product to be both highly reflective and highly heat releasing, multiple, multi-component filler packages in silicone were evaluated for each’s impact on the RTV rubber’s reflectivity and thermal emissivity.

Key Features & Benefits of RTV681-LV

  • Excellent thermal control properties
    • Highly reflective – typical solar absorption of 0.16 at 0.006” thickness
    • Thermal emittance greater than 0.88
    • Non-specular coating
  • Can be diluted with a silicone fluid to make various different material application techniques possible
  • Meets ASTM E595 for low outgassing applications – to minimise contamination under vacuum and high temperature exposure
  • Dielectric insulator
  • Simple processing
    • 1:1 by weight mix ratio to ease use
    • Long working time at 77F/50%RH
    • Fast, full cure from 1hr at 100°C~150°C, to enable continuous production
    • Can also cure at room temperature
  • Even after hundreds of hours of elevated temperature or UV exposure, it remains highly reflective
  • Radiation and Atomic Oxygen stability
  • The flexible coating is capable of performing a 3.2mm (0.125in) bend radius down to -60°C

Potential Applications for RTV681-LV

This product is ideally suited for applications where there is a requirement for a passive thermal control coating. These applications include:

  • Satellites
  • Aerospace
  • Aviation
  • Sensors