Analysis of Physical-Chemical Properties and Space Environment Adaptability of Two-Component RTV Silicone Rubber

Silicone rubber (SR) has the properties of organic-inorganic materials and good adaptability to the space environment, which can be used as an atomic oxygen (AO)-resistant layer on the spacecraft surface. In this study, SR coatings were used to spray on the polyimide surface to prevent atomic oxygen erosion. Then, the physical, chemical, and AO-resistant properties of the SR were investigated. By means of laser diffraction scattering particle size distribution tests, energy-dispersive spectroscopy elemental mapping, and X-ray photoelectron spectroscopy, the fillers and matrix were confirmed as precipitated silica and phenyl SR, respectively. Through analysis of swelling behavior, greater cross-linking density and less swelling ratio were observed at higher temperature and humidity. Furthermore, after AO was exposed with an accumulated fluence of 1.2 x 10(21) atoms/cm(2), cracks appeared on the coating surface with the change of element content. In addition, it was found that the degree of reaction between AO and SR should not be determined based on mass loss measurements. Our work showed the practical application and great potential of SR protective coating in spacecraft.

Automated summary

This study explored the use of silicone rubber coatings to protect spacecraft surfaces from atomic oxygen erosion, revealing increased cross-linking density and reduced swelling ratio under high temperature and humidity conditions. Cracks were observed on the coating surface after exposure to atomic oxygen, and the degree of reaction between atomic oxygen and silicone rubber cannot be accurately determined through mass loss measurements.