Development of Rain-Erosion-Resistant Coatings for High-Speed Aircraft

Research on development of a thermally stable, rain-erosion-resistant coating has involved, mainly, three types of polymers made from hexafluoroacetone, alkenes, and silicon-containing compounds. In addition, a silphenylene-dimethylsiloxane elastomer has been given a preliminary evaluation. The polymers based on hexafluoroacetone cure at room temperature to elastomers that have good resistance to heat and liquid fuels. More work is needed to increase molecular weights and improve tensile properties. The initial work on copolymerizing a low molecular weight polyacrylic acid with nylon is continuing. With this material, an 11 percent fixation was achieved on nylon fabric, almost the double the amount obtained with the higher molecular weight polyacrylic acid.