论文部分内容阅读
Novel shish-kebab type liquid crystalline poly(p-phenylenevinylene) derivatives were synthesized by Stille coupling reaction from 2,5-bis[(4-n-alkoxyl)benzoyloxy]l,4-dibromobenzene (monomer 1) and 1,2-bis(tributylstannyl) ethylene (monomer 2). The polymers with alkoxy groups are soluble in common organic solvents and exhibit blue fluorescence. Both the cast film and the annealed film have large red-shifts in fluorescence spectra and show yellow fluorescence. The polymers with CN and NO2 groups show poor solubility and green fluorescence. All the polymers possess liquid crystalline smectic phases. The melting point (Tm) of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The polymers are easily aligned under a magnetic field of 10 Tesla. It is found that the conjugated backbone and LC side chain are aligned perpendicular and parallel to the magnetic field, respectively. The polymers show optical dichroism in fluorescence spectra, suggesting that they are available for advance materials with linear optical polarization.
Novel shish-kebab type liquid crystalline poly (p-phenylenevinylene) derivatives were synthesized by Stille coupling reaction from 2,5-bis [(4-n-alkoxyl) benzoyloxy] The polymers with alkoxy groups are soluble in common organic solvents and exhibit blue fluorescence. Both the cast film and the annealed film have large red-shifts in fluorescence spectra and show yellow fluorescence. The polymers with The melting point (Tm) of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The polymers are easily aligned under a Magnetic field of 10 Tesla. It is found that the conjugated backbone and LC side chain are aligned perpendicular and parallel to the magnetic field, respectively. The polymers show optical dichroism in fluorescence spectra, suggesting th at they are available for advance materials with linear optical polarization.