Study Of Process Conditions Of4,4’-Bis(chloronmethyl)-1,1’-Biphenyl Self-polymerization,Chemical Modification And Their Hydrogen Storage Properties

Hypercrosslinked resin, which has large surface areas, rich porous structure, excellent swelling properties of a variety of solvents and good adsorption property of hydrogen at low temperatures, is one kind of promising hydrogen adsorption materials.The self-polymerization adsorption resin of4,4’-bis(chloromethyl)-1,1’-biph-enyl(BCMBP), which are aromatic hydrocarbons with two chloromethyl, have been obtained by continuous F-C alkylation of monomer in the homogeneous solution. Compared to the synthesis of the traditional polystyrene hypercrosslink-ed resin, the method above is very convenient in one step to get the product. The resulting resin has very high specific surface area, narrow pore size distribution (mainly is the micropores and low mesoporous), continuous gel structure and high pore volume. The optimum process conditions of the self-polymerization of BCMBP have been achieved by orthogonal experiments. The result is shown as following:the pre-polymerization temperature is60℃; the pre-polymerization time is3hours; the monomer concentration is7%; and the concentration of catalysts FeCl3is0.5mol/mol.Based on above work, nitro-, sulfonyl-, amino-and hydroxyl-resins were synthesized by chemical modification of self-polymerization resin of BCMBP. The chemical structure, pore structure and pore morphology of these resins were charactered by IR, low-temperature nitrogen adsorption-desorption, elemental analysis and scanning electron microscopy. The adsorptive performance of these resins and the amount of hydrogen storage were studied by low-temperature hydrogen adsorption-desorption. The amount hydrogen storage of self-polymeriz-ation resin of BCMBP can reach1.92wt%when the partial pressure of hydrogen is one standard atmosphere and temperature is77K, which is larger than that of commercial resins. In the same conditons, the hydrogen storage capacity of the resins that were modified by nitro, sulfonicacid, hydroxy, amino were1.75,1.83, 2.01,2.03wt%respectively. It can be concluded that resins with the electron withdrawing groups have a lower hydrogen storage capacity. On the contrary, the hydrogen adsorption capacity of resins is greatly improved with the introduction of electron donating groups. Electron cloud density around the benzene ring is very important for the hydrogen storage capacity of materials. The electron withdrawing groups can passivate benzene ring, while electron donating groups can activate the benzene ring.