Syntheses, Characterization,and Properteis Of Substituted Poly(3,4-dioxythiophene)s

Unsubstituted Poly(3,4-dioxythiophene)s in its pure form suffered from some disadvantages such as poor processability, poor flexibility and less functionality, thus preventing these conducting polymers from making significant commercial impact in diverse fields such as organic electronics, chemical sensors, energy storage,biomedical engineering. Therefore, Syntheses of novel conductive polymer with good solubility and functionality is very meaningful.Firstly, Triethylene glycol-functionalized poly(3,4-propylenedioxythiophene)s were prepared by combination of GRIM and postpolymerization modification approach. Copolymerization of ProDOTBu2Br2 and ProDOTNorBr2 by GRIM afforded norborene functionalized poly(3,4-propylenedioxythiophene) copolymers.Pendent norborenes in the copolymer were quantitatively converted to hydrophilic triethylene glycol group by reaction with excess 1-azido-2-(2-(2-meth oxyethoxy)ethoxy)ethane under mild reaction conditions. The hydrophilic properties of the resulting modified polymers could be modulated by varying the copolymer compositions. This particular combination of GRIM and norborene-azide click reaction creates a new platform for the preparation of poly(3,4-propylenedioxythiophene)s with diverse functionalities via azide-mediated click reactions.Secondly, novel hydroxyl-functionalized poly(3,4-propylenedioxythiophene)s were synthesized via a combination of Grignard metathesis(GRIM) polymerization and subsequent thiol-halgon click-like reaction. Copolymerization of ProDOT(Bu)2Br2 with ProDOT(CH2Br)2Br2 by GRIM gave the bromide containing polydioxythiophene copolymers in reasonable yields and molecular weights with narrow molecular weight distribution. Then pendent bromides in the copolymer were quantitatively converted thioether group by reaction with 2-mercaptoethanol under mild reaction conditions to afford hydroxyl-functionalized poly(3,4-propylenedioxythiophene)s.Thirdly, Photopolymerization of urethane acrylate(PUA) containing dibutylsubstituted poly(3,4-propylenedioxythiophene)(Poly(ProDotBu2)) was applied on Q235 carbon steel to afford the PUA/Poly(ProDot Bu2) composite coatings. The anticorrosion behavior of polyurethane acrylate(PUA)/Poly(ProDotBu2) composite coatings was studied by electrochemical techniques including open-circuit potential(OCP), potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS). It was observed that the PUA/Poly(ProDotBu2) composite coatings exhibited an excellent corrosion resistance and barrier properties in comparison with pure PUA coating.Finally, polystyrene-functionalized poly(3,4-ethyldioxythiophene)s were synthesized via a combination of atom-transfer radical polymerization(ATRP) and C-H direct arylation polymerization. In the first step, benzyl bromide EDOT-Ph-MeBr as the initiator, styrene as the monomer, pendent different polystyrene long-chain EDOT macromolecular monomer has been afforded by ATRP polymerization under the suitable condition.Then this macromolecular monomer and EDOT-C10-Br2 by C-H direct arylation polymerization gave the resulting copolymer in reasonable molecular weights with narrow molecular weight distribution. Besides,All the resulting copolymers exhibited UV-vis absorption peaks between 550-620 nm,and showed fluorescence emission.