Preparation And Microwave Absorbing Properties Of Conducting Polymer Composites

About the microwave absorbing properties of conducting polymers, currently, the research focused on the following aspects: (1) Improve and control the structure and morphology of conductive polymers; (2) prepare the composites of conducting polymer and magnetic loss inorganic materials (magnetic metals, ferrites, and magnetic oxides) to improve the dielectric loss and magnetic loss, and finally improve the microwave absorbing properties;(3) Prepare the copolymer of different conductive polymers, to improve the conducting polymer dielectric properties. But compare with the researches about different conductive polymer composite microwave absorbing properties and mechanism, the reports about the composites of different conducting polymers are still very little. This thesis based on two typical conductive polymers, polyaniline and polypyrrole, prepare the conducting polymer composites, which have core-shell structure and different morphology, under different solution by chemical oxidation polymerization. Characterize the material and research the microwave absorbing properties by infrared spectroscopy (FT-IR) analysis, UV - visible spectroscopy (UV-Vis), scanning electron microscopy (SEM) analysis, the four-probe tester and vector network analyzers.In HCl, cetyltrimethyl ammonium chloride (CTAC) as the surfactant, ammonium persulfate (APS) as the oxidant, prepared polypyrrole, the structure of this polypyrrole is space reticular structure constituted by the polypyrrole ball around 200 nm. The conductive polymer composite material (PPy-PANI) still retains the polypyrrole reticular structure, the complex mechanism is physical complex, the composite of PPy-PANI, which contain polypyrrole 80wt.%, shows the maximum absorption strength of composite materials as 43dB; The band width greater than 10 dB of the composite of PPy-PANI, which contain polypyrrole 80wt.%, is up to 5.5 GHz.Polypyrrole prepared in the ferric chloride (FeCl3) solution, and hydrogen peroxide (H2O2) as the oxidant is ball about 300 nm, uniform particle size, well dispersed, and no cross-linking, smooth surface. The composite materials (PPy-PANI) still is ball, good dispersion, the mechanism is still physical complex. After microwave absorbing properties of composite material is greater than polypyrrole significantly, the maximum absorption is -9 dB, where the pure PPy is almost zero.The particle size of polypyrrole prepared in P123 system reduced as the concentration of P123, and under the same conditions, the stacking density decreased as the reaction time increases. Dielectric properties show that the composite of PPY-PANI, which contain polypyrrole 80wt.%, have the peak of resonance at 3 GHz and 8 GHz.