| Material plays an important role in human’s development, it has been concern in the scientific community. As a common porous material, organic porous polymer (POPs) not only have low skeletal density but also have high surface area and large total pore volume. POPs have potential applications in terms of energy gas adsorption and storage, such as hydrogen gas and methane gas. Some POPs are also used in volatile organic compounds (VOCs) control. Because of the diversity of its synthetic methods, we can choose the fit building blocks to design and synthesize POPs with specific structure and properties as expected.In this thesis, we foused on the design, synthesis, characterization and adsorption capability of hypercross-linked polymers (HCPs), which have many advantages such as low cost, simple monomer and mild reaction conditions. The main content and conclusions of this paper are:(1) Five different aromatic compounds, styrene, benzyl chloride, methyl ether, trifluorotoluene and triphenylmethane were selected as monomers and formaldehyde dimethyl acetal (FDA) was used as an external cross-linker. Through one-step Friedel-Crafts cross-linking approach, we synthesized five different organic porous polymers. From the characterization data, we found the benzyl chloride-based network had the best porous properties. Based on the experimental results, the benzyl chloride was selected as one reactant to react with different amount of FDA. The results indicated that the surface area and pore volume also can be controlled by adjusting the external cross-linker ratio. The highest BET surface area (1394m2/g) and largest pore volume (1.55cm3/g) were obtained over the Cl-0.5sample.The Cl-0.5sample had a good adsorption capacity for benzene vapor with a maximum adsorption capacity of19.2mmol/g (298K).(2) Four self-crosslinking POPs were synthesized via Friedel-Crafts alkylation reaction using different concentrations of1,4-bis(methoxymethyl)benzene as reactants, different amounts of FeCl3as a catalyst. There are a variety of morphologies coexisted in the self-crosslinking polymers determined by using the scanning electron microscopy (SEM) technique. The morphology of the network structure for the synthesized POPs was different as compares with the reported in literature. There were not only different sizes of polymeric microspheres particle accumulation but also the formation of amorphous polymeric sheet which formed irregular polygonal pores simultaneously.(3) A simple one-step Friedel-Crafts reaction of a new cross-linker4-bis(methoxymethyl)benzene and aromatic compounds benzyl chloride as monomer were used to react at25℃and80℃, respectively. A series of HCP-X-25and HCP-X-80polymerization products with high specific surface area and large pore volume were synthesized at different temperatures. The pore structure data of the samples synthesized were obtained using nitrogen physisorption characterization. The porous structure of the smaples synthesized at room temperature (25℃) had the same pore properties as compared with the samples synthesized at80℃. The highest BET surface area of1345m2/g for HCP-1.5-25sample and the maximum total pore volume of1.92cm3/g for HCP-1-25sample were obtaind. Considering the effect of temperature on the pore structure, benzyl chloride as a monomer and4,4’-bis(methoxymethyl) biphenyl as a cross-linker were used to synthesize the XIN-1-25sample at25℃. The BET surface of XIN-1-25sample reached to1017m2/g and, the pore volume reached to0.84cm3/g. The HCP-1-80sample with maximum total pore volume among all samples was investigated by the adsorption behavior of benzene vapor at different temperatures, the maximum adsorption amount of benzene vapors was up to20.2mmol/g (318K). |
PDF Full Text Request