Thiophene-based Microprous Organic Polymers:Preparation,Characterization,and Gas Storage

Microporous organic polymers, which are composed of light, non-metallic elements such as C, H,O, N, and B, connected through covalent bond, possess high specific surface area and a large number of micropores. Compared with traditional porous materials, such as zeolites and activated carbon,microporous organic polymers are new-style materials, and possess a number of special features, such as low skeleton density, high specific surface area, tunable pore properties, outstanding physicochemical and thermal stability, and various skeleton molecular structures. They have promised application in diverse technological fields, such as heterogeneous catalysts, gas storage and separation, and organic electronic materials. Therefore, microporous organic polymers have attracted considerable attention and are becoming an important class of microporous materials.In this thesis, a series of thiophene-based porous organic polymers with high sulfur content were prepared. The chemical constitutions of these polymers were characterized. The applications of them in gas adsorption were also studied.Part ?: All-thiophene-based Porous Organic Polymers: Synthesis, Characterization and Efficient Gas StorageTwo all-thiophene-based monomers cycloocta[1,2-b:4,3-b':5,6-b'':8,7-b''']tetrathiophene and benzo[1,2-b:3,4-b':5,6-b'']trithiophene were synthesized. Then two novel all-thiophene-based conjugated porous organic polymers(Th POP-1 and ThPOP-2) were synthesized through ferric chloride-catalyzed oxidative coupling polymerization. Two obtained polymers were characterized via solid-state 13 C CP/MAS NMR spectroscopy, the Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and elemental analysis. The Brunauer-Emmett-Teller specific surface area is 1050 and 160 m2 g-1 for ThPOP-1 and ThPOP-2, respectively. Carbon dioxide adsorption isotherms show that ThPOP-1(15.0wt%) exhibits a larger uptake capacity than that of Th POP-2(4.0 wt%) at 273 K and 1.0 bar. Hydrogen uptake is also excellent for Th POP-1(2.23 wt%) and ThPOP-2(1.03 wt%) at 77 K and 1.0 bar.Part ?: Thiophene-based Conjugated Microporous Polymers: Synthesis, Characterization andEfficient Gas StorageWith ethene and benzene as cores, four thiophene-based monmers 1,1,2,2-tetra(thiophen-2-yl)ethene, 1,3,5-tri(thiophen-2-yl)benzene, 1,2,4,5-tetra(thiophen-2-yl)benzene, 1,2,3,4,5,6-hexa(thiophen-2-yl)benzene were synthesized. Four thiophene-based conjugated microporous polymers, ThPOP-3,ThPOP-4, ThPOP-5, Th POP-6, have been synthesized, respectively, based on ferric chloride-catalyzed oxidative coupling polymerization. The structures of these obtained polymers were confirmed by Fourier transform infraed spectroscopy and solid-state 13 C CP/MAS NMR spectroscopy. The polymer ThPOP-3,bearing the ethene core, possesses very low Brunauer-Emmett-Teller specific surface areas(346 m2 g-1)All other polymers bearing the benzene core, exhibit high Brunauer-Emmett-Teller specific surface areas above 1000 m2 g-1. All of these four polymers are microporous with the pore size less than 2 nm. The carbon dioxide adsorption isotherms show that these polymers bearing the benzene core have better carbon dioxide adsorption than that of ThPOP-3, which has the ethene as the core. The polymer ThPOP-4 have the best carbon dioxide adsorption up to 15.34 wt% at 273 K and 1.0 bar. The ThPOP-5 has the best hydrogen uptake up to 2.17 wt% at 77 K and 1.0 bar, higher than that of other polymers.