Synthesis, Characterization And Electromagnetic Wave Absorbing Properties Of Ferrocenely-Chiral Schiff Base Polymers

Chiral absorbing material is a new kind of electromagnetic absorbing material with helical structure. Compared with ordinary absorbing material, Chiral absorbing material has some advantages: Firstly, the helical structure in chiral absorbing material can cause the crossing polarization in electromagnetic field and obtain better absorbing performance; Secondly, the chiral parameters can be modified and achieve better electromagnetic impedance matching effect. In addition, the frequency sensitivity of the chiral material is lower than the electromagnetic permeability, which can obtain a certain degree of absorption in a wide frequency band. Ferrocenyl chiral poly Schiff base/RGO is a new type of chiral polymer absorbing material, which combines the advantages of chiral absorbing material, magnetic organic ferrocene-ploymers and RGO. The improved absorbing performance and extend absorbing bandwidth of ferrocenyl chiral absorbing material were obtained.There are several main works below:(1) 12 kinds of chiral ferrocenecarboxaldehyde poly Schiff bases with their iron(II) salts and 3 kinds of achiral ferrocenecarboxaldehydepoly poly Schiff bases with their iron(II) salts were synthesized in Friedel-Crafts reaction. Their structures were characterized through IR, element analysis and optical rotation. The iron(II) ion contents of poly Schiff base iron(II) salts were measured. Their electrical conductivities were measured using a four-point tester. Chiral features have no effect on the conductivities of poly Schiff base iron(II) salts.(2) 4 kinds of chiral 1,1-diacetyl ferrocene poly Schiff bases with their iron(II) salts and 3 kinds of achiral 1,1-diacetyl ferrocene poly Schiff bases with their iron(II) salts were synthesized. Their structures were characterized through IR, element analysis and optical rotation. The iron(II) ion contents of poly Schiff base iron(II) salts were determined. Their electrical conductivities were measured using a four-point tester. The electrical conductivities of poly Schiff base iron(II) salts have at least 3 orders of magnitude improvement than poly Schiff bases.(3) 14 kinds of chiral ferrocenyl Schiff bases iron(II) salts/RGO composite materials and 6 kinds of achiral ferrocenyl Schiff bases iron(II) salts/RGO composite materials were synthesized by solution blending method. The difference in chiral diamine and carbon chain length of ferrocenyl Schiff bases were studied. The conductive properties and absorbing properties of chiral absorbing materials were compared with non-chiral absorbing materials. Experimental results show that the absorbing properties of chiral absorbing materials were better than achiral, in which, reflection losses of composite CM-PL1 B obtained-52.6 dB at 10.1 GHz with a thickness of 2.5 mm.