Preparation And Absorbing Properties Of Chiral Poly Schiff Bases

Chiral absorbing material is a isotropic magnetic material with helical structurewhich can produce cross-polarization coupling in the electromagneticfield.Comparing with ordinary absorbing material, there are two advantages: firstly, itcan meet requirements of no reflection on the wide band for chiral parameter is moreeasily adjusted than dielectric parameter and permeability; secondly, the frequencysensitivity of chiral materials is less than dielectric parameter and permeability so thatit is easy to broadband absorption. Chiral conductive poly Schiff-base which has easyproduction process and wide variety of sources is a new type of chiral absorbingmaterials, electromagnetic shielding, and has a great potential on extending band andabsorbing on the low-frequency.In this paper, ten chiral poly Schiff bases and twenty metal complex weresynthesized and were characterized by infrared, specific rotation, ICP. Theconductivity of the compounds have been tested. Two kinds of Schiff bases salt weredoped with carbon nanotubes and magnetic materials, composite prepared two newcomposite absorbing materials and the absorbing properties were measured. Thepaper is divided into four parts.1. The synthesis method of the Schiff bases have been introduced, The researchprogress of general radar absorbing materials and chiral absorbing materials werereview.2. Five kinds of chiral Schiff bases of (R,R)-1,2-propanediamine have beendesigned and synthesized. Ten kinds of chiral poly Schiff bases salt were synthesizedwith transition metal. The structures of the compounds have been characterized byinfrared, specific rotation, ICP. The conductivity of the compounds have been tested.3. Five kinds of chiral Schiff bases of (R,R)-1,2-cyclohexanediamine have beendesigned and synthesized. Ten kinds of chiral poly Schiff bases salt were synthesizedwith transition metal. The structures of the compounds have been characterized byinfrared, specific rotation, ICP. The conductivity of the compounds have been tested.4. Two chiral Schiff bases salt were doped with conductive material X and twomagnetic materials. Four new composite absorbing materials have been made. Thethermal stability, conductive properties and microwave absorbing properties ofcomposite have been tested. The results research show that composite have excellentmicrowave absorbing properties in the13GHz~16GHz range and the maximum reflection loss can reach-17.76dB.