Synthesis And Characterization Of Carbazole Or Azobenzene Functionalized Polyether

Polyether showed many interesting properties due to its characteristic water and organic soluble property accompanied with the special crystalinity behavior. Using the polyether as the building block, many kinds of functional materials have been prepared, such as block copolymers, comb-polymers and star copolymers. In this thesis, two functionalized polyethers were synthesized via ring-opening polymerization (ROP) and nitroxide-mediated free radical polymerization (NMP). The properties of these materials were characterized at the same time. The detailed works were summarized as the following:(1) The macro-TEMPO agent (poly(4-glycidyloxy-2,2,6,6-tetramethylpiperidine -1-oxyl), PGTEMPO) was synthesized by anion ring-opening polymerization (ROP) of 4-glycidyloxy-2,2,6,6-tetramethyl-piperidine-1-oxyl (GTEMPO) using potassium t-butoxide as the initiator. The comb-shaped copolymer, PGTEMPO-g-PVBK, was prepared via nitroxide-mediated free radical polymerization (NMP) using PGTEMPO as macro-TEMPO agent and 9-(4-vinylbenzyl)-9H-carbazole (VBK) as the monomer. The polymerizations showed characteristics of"living"/controlled behavior. The optical properties, thermal analysis and electrochemical properties of the comb-shaped copolymers were investigated. The fluorescence and ultraviolet intensity and cyclic voltammetries of the comb-shaped copolymers with different molecular weight showed a regular order.(2) Azobenzene functionalized polyethers were synthesized by anion ring-opening polymerization (ROP) of p-methoxyazobenzene functionalized epoxy monomer (MMAZO) using potassium t-butoxide as the initiator. The polymers were characterized with respect to their molecular weights, structure, and calorimetric features. The photoisomerization of PMMAZO in chloroform solution was investigated by UV-vis absorption spectra on irradiation at 365 nm. The crystallinity behaviors of polyether (PMMAZO) bearing p-methoxyazobenzene moieties in the side chain were characterized by combination techniques consisting of differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The results showed that the polymer exhibited a smectic phase and a nematic phase transition and showed complicated crystalline behavior during the heating process.