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    Yuhan Li

    Jin, R., Li, Y., Xing, W., Qiu, X., Ji, X. and Gao, L.(2012), Preparation and properties of ionic cross-linked sulfonated copolyimide membranes containing pyrimidine groups. Polymers for Advanced Technologies, 23: 31–37. doi: 10.1002/pat.... more
    Jin, R., Li, Y., Xing, W., Qiu, X., Ji, X. and Gao, L.(2012), Preparation and properties of ionic cross-linked sulfonated copolyimide membranes containing pyrimidine groups. Polymers for Advanced Technologies, 23: 31–37. doi: 10.1002/pat. 1835
    A series of sulfonated polyimides (SPIs) containing pyridine ring in the polymer backbone were synthesized by the polycondensation of 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTDA), 5-(2,6-bis(4-aminophenyl)pyridin-4-yl)-2-methoxy... more
    A series of sulfonated polyimides (SPIs) containing pyridine ring in the polymer backbone were synthesized by the polycondensation of 1,4,5,8-naphthalene-tetracarboxylic dianhydride (NTDA), 5-(2,6-bis(4-aminophenyl)pyridin-4-yl)-2-methoxy benzene sulfonic acid (SDAM), and 4,4′-diaminodiphenyl ether (ODA). Flexible, transparent, and tough membranes were obtained. Property study revealed that all the membranes displayed high thermal stability with the desulfonation and decomposition temperature higher than 290 and 540°C, respectively, as well as good mechanical property with Young's modulus larger than 1.0 GPa, maximum strength (MS) on a scale of 60–80 MPa, and elongation at break (EB) ranged from 41.79 to 75.17%. More importantly, the new materials exhibited small water uptake and excellent dimensional stability with the highest sulfonated SPI-80 showing the maximum water uptake of 36.1%, and maximum swollen ratio of Δt = 0.038 and Δl = 0.026, respectively (Δt and Δl stands for the thickness and diameter change of the film, respectively). The high water stability exhibited by the SPI films is attributed to the formation of inner salts and/or ionic crosslinking between the sulfonic acid and pyridine functional groups, which suppresses the water uptake ability of sulfonic acid and strengthened the interpolymer chain interactions. Thus, the excellent water stability, good thermal and mechanical properties, and the technologically applicable conductivity of SPI-80 render this material attractive for proton exchange membrane (PEM) application. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
    A novel sulfonated diamine monomer, 1,4-bis(4-aminophenoxy)-naphthyl-2,7-disulfonic acid (BAPNDS), was synthesized. A series of sulfonated polyimide copolymers were prepared from BAPNDS, 1,4,5,8-naphthalenetetracarboxylic dianhydride... more
    A novel sulfonated diamine monomer, 1,4-bis(4-aminophenoxy)-naphthyl-2,7-disulfonic acid (BAPNDS), was synthesized. A series of sulfonated polyimide copolymers were prepared from BAPNDS, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) and nonsulfonated diamine 4,4′-diaminodiphenyl ether (ODA). Flexible, transparent, and mechanically strong membranes were obtained. The membranes displayed slightly anisotropic membrane swelling. The dimensional change in thickness direction was larger than that in planar. The novel SPI membranes showed higher conductivity, which was comparable or even higher than Nafion 117. Membranes exhibited methanol permeability from 0.24 × 10−6 to 0.80 × 10−6 cm2/s at room temperature, which was much lower than that of Nafion (2 × 10−6 cm2/s). The copolymers were thermally stable up to 340 °C. These preliminary results have proved its potential availability as proton-exchange membrane for PEMFCs or DMFCs.
    Ru/C was found to be a highly effective catalyst for the selective partial hydrogenation of a range of dinitrobenzenes to their corresponding nitroanilines with excellent selectivity under mild conditions. Furthermore, the effect from... more
    Ru/C was found to be a highly effective catalyst for the selective partial hydrogenation of a range of dinitrobenzenes to their corresponding nitroanilines with excellent selectivity under mild conditions. Furthermore, the effect from other substitute groups of dinitrobenzenes on ...