Synthesis And Opoelectronic Properties Of Novel Conjugated Polymer

Conjugated organic polymeric molecules have potential applications in molecular sensors, non-linear optical materials, organic field effect transistors, photoluminescence, and electroluminescence. In this thesis, some novel anthracene- containing and terfluorene-containing polymers have been synthesized and their Two-photon absorption(TPA),electroluminescent and thermal properties have been investigated. These include:1. The synthesis of new blue-emitting polymers with thermal- and photo- stability and with an improved imbalance of the hole and electron transport are needed. Poly-fluorene is an important blue-light emitting material, here our goal is to investigate whether the integration of different segments, each having respective functions, endow a copolymer with improved optoelectronic properties. Thus a novel blue-emitting alternating benzofuran/ter-?uorene copolymer with pendent oxadiazole groups (PBF-OXD) has been synthesized. The results showed that PBF-OXD shows good thermal and optical stability, a high glass transition temperature, and high ?uorescence quantum yield. A simple EL device with the configuration of ITO/PEDOT:PSS/PBF-OXD/Ba/Al displays a stable blue emission (λmax = 434 nm),, a maximum brightness of 1400 cd?m-2, and a maximum luminance efficiency of 0.95 cd?A-1. These results show that this solution processable alternating benzofuran/ ter?uorene copolymer is a good candidate for a stable blue-emitting material.2. The design and synthesis the conjugated polymers with large Two-photon absorption cross section are very important. To the best of our knowledge, poly(2,6-anthracenevinylene)s (PAV) and 2,6-anthracenevinylene- containing polymers are very scarce at present because of their synthetic inaccessibility before. Here we design and synthesize two novel donor-containing poly(2,6-anthracene- vinylene)-based derivatives (P1 and P2) by Wittig–Homer reaction between 9,10-bis(3,4-bis(2-ethylhexyloxy)phenyl)-2,6-bis (diethylphosphory lmethyl) anthrax- cene and N-octyl-3,6/2,7-diformylcarbazole. The results showed that P1 and P2 have high-fluorescence quantum yields (Φf = 0.85–0.78). The maximalδof P1 and P2 are 840 GM and 490 GM per repeating unit, respectively. Theseδvalues are obviously higher than that (210 GM) of their reference polymer, PAV, indicating that the incorporation of strong electron-donating moieties into the polymer backbone to form D–π–D repeating unit is more effective in enhancingδthan the extension of conjugation length.3. Anthracene is a large and planner aromatic ring, which improves the rigidity and glass transition temperature of the resulting polymers through its steric hindrance. Anthracene is also a functionalized moiety, which may perform dimerization or endo-peroxidation to form a crosslinking polymer. Here we incorporate a new bisphenol monomer containing anthracene, 9,10-bis(4-hydroxyphenyl)anthracene to the polycondensation of bisphenol A and 4,4'-dichlorodiphenyl sulfone, to synthesize novel anthracene-containing poly(arylene ether sulfone)s.These polymers showed increased glass transition temperature with the content of the 9,10-diphenylanthracene and reached up to 265℃when the bisphenol A was substituted by bis(4- hydroxyphenol)anthracene. These polymers are soluble and can be film-formed through spin-coating. Moreover, upon irradiating with UV-vis light and then heating in air, the resulting film was a cosslinked polymer, which offers the possibility of enhanced thermal.