Study On Synthesis And Properties Of Alternating Copolymers Containing Ionic Conductivity

Several light-emitting polymers containing alternative strong polar ionic conductive segments(PEO) and apolar conjugated segments on the backbone(derivatives of PPV) have been synthesized through Wittig and Mitsunobu reaction. They were characterized by Fourier Transform Infra-red spectroscopy (FT-IR), Proton Nuclear Magnetism Resonance (1H-NMR), Elemental Analysis, electrochemistry analysis , Ultraviolet-visible spectroscopy (UV-Vis), Gel Permeation Chromatography (GPC), fluorescence spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry(DSC). Their luminescence properties were also studied. The crystallization and morphology of copolymers have been studied through X-Ray diffraction meter(XRD), Polarized optical microscope(POM), Phase contrast microscope and Atomic force microscope(AFM). The results are as follows:The PEO units afford polymers not only ionic conductive function, but also good solubility, processable properties. And the polymers showed high luminescence efficiency if the lengths of PEO units in the polymers backbone is enough.Compared with P1 and P3 ,introduction of two methoxy groups into the central benzene ring of PPV not only modifying the electronic structure and photophysical properties, but also greatly increasing the quantum efficiency.The solubility of LiCF3SO3 in the luminescent materials can be improved if PEO were added to the materials ,but phase separation can not be avoided.The relationship of PEO chain length with crystallization, phase structure and solvency to the LiCF3SO3 of copolymers were investigated. A proposal was offered for a rational design of this kind of copolymers.