文献类型：期刊文献

英文题名：Polycyclotrimerization of diynes: Synthesis and properties of hyperbranched polyphenylenes

作者：Xu, Kaitian[1]; Peng, Han[1]; Sun, Qunhui[1]; Dong, Yuping[1]; Salhi, Fouad[1]; Luo, Jingdong[1]; Chen, Junwu[1]; Huang, Yi[1]; Zhang, Dezhen[1]; Xu, Zhongde[1]; Tang, Ben Zhong[1]

机构：[1]Hong Kong Univ Sci & Technol, Dept Chem, Inst Nano Sci & Technol, Ctr Display Res, Kowloon, Hong Kong, Peoples R China;[2]Hong Kong Univ Sci & Technol, Inst Mol Technol Drug Discovery & Synth, Open Lab Chirotechnol, Kowloon, Hong Kong, Peoples R China;[3]E China Univ Sci & Technol, Inst Polymer Sci & Engn, Shanghai 200237, Peoples R China

年份：2002

卷号：35

期号：15

起止页码：5821

外文期刊名：MACROMOLECULES

收录：;EI(收录号：2002327049002);WOS:【SCI-EXPANDED(收录号:WOS:000176814600019)】；

语种：英文

外文关键词：Differential scanning calorimetry - Glass transition - Light scattering - Molecular weight - Nuclear magnetic resonance spectroscopy - Optimization - Synthesis (chemical) - Thermodynamic stability - Thermogravimetric analysis - Viscosity

摘要：Diyne polycyclotrimerizations initiated by transition-metal catalysts afforded hyperbranched polyphenylenes, which exhibited low viscosity, outstanding thermal stability, and small optical dispersion. Under optimized reaction conditions, polycyclotrimerizations of 1,8-nonadiyne (1) and 1,9-decadiyne (2) catalyzed by TaCl5-Ph4Sn produced hyperbranched poly(1,2,4-benzenetriyl-1,5-pentanediyl) (3) and poly(1,2,4-benzenetriyl-1,6-hexanediyl) (4)(1-5) respectively, in high yields (up to 93%). The polymers were completely soluble and film-forming, and possessed high molecular weights (M-w up to similar to1.4 x 101) but low intrinsic viscosities ([eta] down to 0.13 dL/g). Their structures and properties were analyzed and evaluated by IR, UV, NMR, SEC, TGA, DSC, spectrofluorometry, light scattering, and spectroellipsometry. The structural characterizations confirmed the expected hyperbranched molecular architectures of 3 and 4 (comprising of 1,2,4-benzene rings and alpha,omega-alkyl spacers) and revealed the regioselective feature of the diyne polycyclotrimerizations. Polymers 3 and 4 underwent glass transitions at 43 and 23 degreesC, respectively, and lost almost no weights when heated to similar to500 degreesC. Polymer 3 emitted LTV light upon excitation, whereas 4 was practically nonluminescent. The thin films of 3 were highly transparent (greater than or equal to99.5% transmittance) and displayed an optical dispersion as low as 0.009 in the visible spectral region, much superior to those of the commercially important "organic glasses" such as poly(methyl methacrylate) and polycarbonates.