| Hypercrosslinked resin as the third generation of polymeric adsorbent after the gel resin and macroporous adsorption resin, for the characteristics of excellent micropore structure, higher BET surface areas, and good adsorption properties, has played an important role in petrochemical, environmental protection, biological medicine and separation of plants active ingredient. However, due to the single framework (St-DVB) and high preparation cost of the traditional hypecrosslinked resin, the application was limited to some extent. It has become a common goal for scientific workers of different countries to continuous develop high-performance and low cost hypercrosslinked resin, in order to satisfy the new requirement from the industry. In this paper, non-traditional hypercrosslinked resin with high specific area was prepared by direct Friedel-Crafts alkylation polycondensation. The main content contains four parts.Part One:A series of hypercrosslinked resin with different framework was prepared by self-condensation of1,4-bis(chloromethyl)-benzene (XDC) and4,4’-bis-(chloromethyl)-l,1’-biphenyl (CMB) or co-polycondensation with benzene (BE) and biphenyl (DP). The effects of different monomer and the ratio on the surface areas and pore size distribution of the products were compared. The surface areas of XDC-XDC. CMB-CMB and XDC-CMB resin were1045.23m2/g,1253.23m2/g and1502.75m2/g, respectively. The pore radiuses were centralized below20nm. The degree of the crosslink, surface area and pore volume were increased with the increasing the ratio of dichloromethyl compound or using monomer with high chloromethyl content. The surface areas under dry state and swell state were determined by BET method and dye adsorption method, respectively. The results indicated that, the surface area under swell state is to some extent in proportional to the surface area under dry state, as well as affected by the pore structure and the pore size distribution.Part Two:The adsorption performance of resins with different framework on phenol, naphthol and methylene blue were investigated. The effect of pore structure of the resins and molecular size of the adsorbors on the adsorption performance were reviewed, the adsorption capacity and adsorption rate of compounds with varies size on different resins were determined. The results show that resins which obtained by self-condensation or co-polymerization of dichloromethyl compound have higher surface area, and the adsorption capacities on phenol, naphthol and methylene blue were also higher. To the adsorption of small size compound, the adsorption capacity was mainly affected by the surface area of the resin; it was increased with the surface area of the resin. The thermodynamic adsorption data showed that Langmuir and Freundlich isotherms were found to fit well the adsorption data of three adsorbor onto the eight resins. The exponent factor n>1in Freundlich isotherms equations, the adsorption is thus favorable. Kinetic study showed that the adsorption performance of these resins for phenol, naphthol and methylene blue can be described by a first-order irreversible adsorption rate equation. The rate constants of adsorptions of phenol, naphthol and methylene blue at298K are0.034min-1,0.082min-1,0.011min-1respectively. CMB-CMB resin possesses a quick adsorption rate and high adsorption capacity, and it has good potential for treating the contamination in the water with high removal efficiency.Part Three:Strong acidic (-SO3H) ion exchange hypercrosslinked resins were prepared via introduce sulfonic group on BE-XDC resin. The physic-chemical structure and properties were characterized by FT-IR, elementary analysis and chemical titration respectively. Various factors affecting the sulfonation reaction such as reactive temperature, reactive time and the mole ratio of the sulfonation reagent were optimized. The exchange capacity of the sulfonated resin is up to3.89mmol/g. The adsorption capacities of SBE-XDC resin for Cu2+、Ni2+in aqueous solution were114.97mg/g (1.82mmol/g) and109.09mg/g (1.85mmol/g) respectively, both slightly higher than the theoretic adsorption capacity, it indicate that the micropore of the resin can absorb Cu2+、Ni2+to same extent. The thermodynamic adsorption data showed that Langmuir isotherms were found to fit well with the adsorption data of Cu2+、Ni2+onto the SBE-XDC resin. The adsorption progress was mainly mono layer chemical adsorption, adsorption enthalpy ΔH>0, adsorption free energy ΔG<0and adsorption entropy ΔS>0, it indicate that the adsorption progress was a spontaneous, endothermal and irreversible progress.Part Four:The suspension polymerization with two organic phases was successful adopted to prepare spherical hypercrosslinked resin by self-polycondensation of4,4’-bis-(chloromethyl)-1,1’-biphenyl (CMB). The chemical structure, morphology and pore characteristics of the novel spherical resin were characterized with Fourier transform infrared spectroscopy (FTIR), micrograph and Brunauer-Emmett-Teller (BET). Keep the volume ratio of the two organic phases (nitrobenzene/dimethyl silicon oil)1:5(V/V), dispersant amount1%(V/V),50℃(1h),60℃(1h),70℃(1h) and80℃(4h), adjust the stirring speed, appropriate size products can be obtained. The maximum surface area of the resin bead was1190.02m2/g, and the pore volume was0.714cm3/g. |
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