22424_ftp.pdf

Synthesis and Characterization of Highly Stable Blue-Light-Emitting Hyperbranched Conjugated Polymers RUI WANG,1 WEI-ZHI WANG,1 GUI-ZHONG YANG,1 TIANXI LIU,1 JUNSHENG YU,2 YADONG JIANG2 1Key Laboratory of Molecular Engineering of Polymers of Ministry of Education, Department of Macromolecular Science, Fudan University, Shanghai 200433, People’s Republic of China 2School of Optoelectronic Information, State Key Lab of Electronic Thin Films Integrated Devices, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, People’s Republic of China Received 18 January 2007; accepted 24 September 2007 DOI: 10.1002/pola.22424 Published online in Wiley InterScience (). ABSTRACT: Polyfluorene homopolymer (P1) and its carbazole derivatives (P2–P4) have been prepared with good yield by Suzuki coupling polymerization. P2 is an alternating copolymer based on fluorene and carbazole; P3 is a hyperbranched poly- mer with carbazole derivative as the core and polyfluorene as the long arms; P4 is a hyperbranched polymer with carbazole derivative as the core and the alternating flu- orene and carbazole as the long arms. These polymers show highly thermal stability, and their structures and physical properties are studied using gel permeation chro- matography, 1H NMR, 13C NMR, elemental analysis, Fourier transform infrared spectroscopy, thermogravimetry, UV–vis absorption, photoluminescence, and cyclic voltammetry (CV). The influence of the incorporation of carbazole and the hyper- branched structures on the thermal, electrochemical, and electroluminescent proper- ties