Shish-Kebab-Type Liquid CrystallineFluorene-Phenylene Copolymers:Synthesis and Properties
Shish-kebab-type liquid crystalline (LC) fluorene-pheneylene copolymers have been synthesized to develop new organic materials with linearly polarized dichroism.The polymers are composed of 9,9-di-n-hexylfluorene moiety linked with 2,5-bis (benzoyloxy)-l,4-phenylene one,where the latter is a shish-kebab-type mesogenic unit and the phenylene is located at a center of gravity of the mesogenic unit.The polymers were soluble in common organic solvents.They showed not only interdigited smectic Ad phase,but also strong blue fluorescence.The melting point (Tin) of the polymers increases when the length of the alkoxy tails of the mesogenic units increases.Optical properties of the polymers in film before and after annealing were evolved.Different from polyfluorene homopolymers,the annealed film show a.narrow featureless PL peak located at 412nm,providing an effective way for improving the color purity of polyfluorene derivatives.Optical anisotropies of the oriented polymers using 10 Tesla magnetic field were also studies.It was 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.
Liquid crystalline conjugated polymers Polyfluorene derivatives Linearly polarized dichroism Shish-kebab Blue fluorescence
Shi-jun Zheng Kazuo Akagi Shao-kui Cao
College of the Material Science and Engineering, ZhengzhouUniversity, Zhengzhou 450052,China Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo
国内会议
郑州
英文
100-103
2006-06-01（万方平台首次上网日期，不代表论文的发表时间）