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Development of Asbestos-free and Environment-Friendly Thermal Protection for Aerospace Application

Thermal protection systems (TPS) are components designed to protect the internal and external areas of a rocket motor from high temperatures. There has been studies in Brazil of resin-based polybutadiene hydroxylated (HTPB) loaded with asbestos since the 1970s. Nevertheless, asbestos has been banned in several countries because it is severely harmful to the human health. In this context, the development of asbestos free in flexible thermal protection (FTP) is extremely important. This study evaluates the use of Expanded Perlite (PExp) as an asbestos substitute. Lower densities were observed, which become a very interesting achievement for the aerospace field. Samples with 5 phr of Expanded Perlite showed similar results when comparing with 47 phr of fillers in PTF reference on oxy-acetylene torch test, and a reduction about 20 % of mass loss rate in test with solid propellant, thus showing that Expanded Perlite can replace asbestos in FTP.