Synthesis And Self-assembly Of Aniline Oligomers And Polyaniline

Since the discovery that the conductivity of polyacetylene can be greatly improved after beingdoped,the research of organic conductive polymer has attracted more and more attention.Polyaniline becomes a hot topic in the field of conductive polymer because of its simple synthesis method,easy accessibility for monomer material and good conductivity.It was found that the conductivity of polyaniline is related to its morphology,thus,morphology control of polyaniline is important in preparation of polyaniline.However,polyaniline possesses poor solubility in most of solvents,which lead to difficulty in morphology control of polyaniline.on the other hand,aniline oligomers is soluble in most of solvents.Therefore,in this thesis,several aniline oligomers were synthesized and then their behavior and self-assembled morphology was investigated.The results was expected to be useful for morphology control of polyaniline.The work mainly includes the following three aspects:1.An organic small molecule was obtained by the condensation of 4'4-diphenylmethane diisocyanate with 4-Aminodiphenylamine,and the molecule was used as a template for preparation of synthesize polyaniline with certain ordered morphology.The morphology was characterized by Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),ultraviolet-visible spectroscopy(UV-Vis),scanning electron microscope(SEM)and transmission electron microscope(TEM).Then,through the thermal gravimetric analyzer(TG)and electrochemical workstation,the difference between template-free polyaniline and templated polyaniline in thermal and electrical properties were examined.2.We designed and synthesized three kinds of aniline oligomers,including double-carboxy-terminated aniline pentamer,3,5-diaminobenzoic acid and diphenylamine condensation polymers,and 4-diphenylaminobenzaldehyde derivatives with p-phenylenediamine condensation polymers.The structures and self-assembled morphologies was characterized with NMR and FT-IR spectroscopy,X-ray diffraction(XRD),ultraviolet-visible spectroscopy(UV-Vis),scanning electron microscope(SEM)and transmission electron microscope(TEM).Then,thermal properties of the oligomers was examined by using thermal gravimetric analyzer.3.A new monomer containing aniline dimer and styrene moiety was designed and synthesized.By combining self-assembly and free radical polymerization(SAFP),the polymer nanosheets were prepared successfully.The structures of the monomer and the polymers were characterized by NMR spectroscopy and Infrared spectroscopy.Self-assembly behaviors of the monomer and the polymers were investigated by transmission electron microscope and X-ray diffraction analysis.The results indicated that the new monomer could self-assemble into two-dimensional nanosheets in a mixed solution of toluene and acetone.Moreover,a polymer nanosheet with a size of several micrometers and thickness of 2 nanometer could be obtained by copolymerizing the monomer with N-butyl maleimide.It has been demonstrated that combination of self-assembly and free radical polymerization is a convenient and efficient approach for preparation of polymer nanosheets.