Abstract Silica-based aerogel is an ideal thermal insulator with a makeup of up to 99% air associated with the highly porous nature of this material. Polyurea cross-linked silica aerogel (PCSA) has superior mechanical properties compared to the native aerogels yet retains the highly porous open pore network and functions as an ideal thermal insulator with added load-bearing capability necessary for some applications. Room temperature vulcanizing rubber-RTV 655—is a space qualified elastomeric thermal insulator and encapsulant with high radiation and temperature tolerance as well as chemical resistance. Storage and transport of cryogenic propellant liquids is an integral part of the success of future space exploratory missions and is an area under constant development. Limitations and shortcomings of current cryogenic tank materials and insulation techniques such as non-uniform insulation layers, self-pressurization, weight and durability issues of the materials used, has motivated the quest for alternative materials. Both RTV 655 and PCSA are promising space qualified materials with unique and tunable microscopic and macroscopic properties making them attractive candidates for this study. In this work, the effect of PCSA geometry and volume concentration on the thermal behavior of RTV 655—PCSA compound material has been investigated at room temperature and at a cryogenic temperature. Macroscopic and microscopic PCSA material was encapsulated at increasing concentrations in an RTV 655 elastomeric matrix. The effect of pulverization on the nanopores of PCSA as a method for creating large quantities of homogeneous PCSA microparticles has also been investigated and is reported. The PCSA volume concentrations ranged between 22% and 75% for both geometries. Thermal conductivity measurements were performed based on the steady state transient plane source method.
Highlights We study the feasibility of using compound aerogel/RTV655 for space applications. We assess thermal conductivity of compound aerogel/RTV655 material at 77K and 287K. We study thermal conductivity for varying concentrations of aerogel to RTV655. Thermal conductivity of the compound decreases as the concentration increases. Thermal conductivity of the compound decreases from room to cryogenic temperatures.
Thermal conductivity studies of a polyurea cross-linked silica aerogel-RTV 655 compound for cryogenic propellant tank applications in space
Acta Astronautica ; 91 ; 173-179
2013-06-02
7 pages
Article (Journal)
Electronic Resource
English
Thermal Characterization of Cross-linked Silica Aerogel-RTV 655 for Cryogenic Propellant Tanks
British Library Conference Proceedings | 2012
|British Library Conference Proceedings | 2012
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