Retinyl Schiff Base Salt Preparation And Millimeter-wave Attenuation Performance Study

Retinyl Schiff base salts are used abroad for stealth and electromagnetic protection for their ability of wave absorption, but the application on passive interference materials are not been reported.In this paper, the retinal was prepared by selective oxidation under existence of a mixture oxidizer (CrO₃·R₁R₂NH₂·HX) from vitamin-A that was obtained by phase transfer catalytically hydrolysis of vitamin- A acetate. The retinyl Schiff base was synthesized by retinaldehyde and diamine, and the retinyl Schiff base salt was prepared by dripping the solution of FeCl₃ in alcohol to the product. The melting point, FT-IR and elemental analysis were used to confirm the samples' structure. Then mixed with carbon fiber and used in millimeter-wave interference materials.Carbon fiber/retinyl Schiff base salts composite materials were prepared and the 3mm and 8mm wave attenuation performance testing were analyzed. Results showed that compound materials have an absorption and interference effect for 8mm wave, and the interference effect have more than 30% increase to pure carbon fiber, and p-phenylene diamine retinyl Schiff base salts have a stronger interference on millimeter-wave than 1,2-ethylenediamine retinyl Schiff base salts. Nevertheless, using the current test and experimental conditions, the two kinds of composite have no significant attenuation function on 3mm wave. Fundamental reasons remains to be further discussed.