Studies on the Climatic Resistance of Thiokol and Siloxane Sealant

Experimental results for the long-term full-scale climatic testing of aviation polysulfide and VITEF-1B, VGM-L, VIKSINT U-20-99, and VGF-2M polysiloxane grade sealing materials are presented. The testing have been carried out under open conditions of humid tropical climate characterizing Wanning (Hainan Island, China) and moderately warm climate characterizing Gelendzhik. In order to analyze the reasons for decreasing elasticity and strength, the results of similar testing under the conditions of Moscow, Florida, Arizona, and Vietnam have been used. It is shown that under the influence of radiation, destruction and cross-linking reactions occur that lead to the change in the elasticity of the studied materials.