New Polymers to Protect Space Vehicles

The synthesis and the characterization of new polymeric systems to be used as protective coatings for space vehicles is described. Particular emphasis is placed on ablators which have low irradiation and particle emissivity under the conditions of typical reentry of a space vehicle into the atmosphere. Crosslinking by ionizing radiation in carbon black filled Kel-F and Teflon has been established by mechanical and thermoanalytical methods. Polyaromatic systems such as polyphenylene, metiylated poly-phenylene, poly-benzyl poly-p-xylylene, furthermore phenolic resins and a styrenedivinyl benzene copolymer have been synthesized and investigated by thermogravimetric analysis. In addition Pluton impregnated with poly-vinyl fluoride or crosslinked polystyrene haa been investigated. As a fourth approach towards new ablative materials the synthesis of aromatic fluorocarbon and silicon type ladder polymers was initiated. The research on carbon-filled Teflon indicates a considerable improvement in heat shielding with polymeric cblators in terms of better mechanical properties and lower weight-to-heat dissipation ratios. NEW POLYMERS TO PROTECT SPACE VEHICLES