Study On The Synthesis And Adsorption Properties Of Chelating Resin Containing S And N

Chelating resin is an important functional material, which is widely used in separation and enrichment of metal ions. At present, chelating resin prepared by traditional method has low density of functional groups and thus exhibit low adsorption capacity.In this paper,two kinds of high-capacity chelating resin was prepared by a new technology atom transfer radical polymerization(ATRP). The adsorption properties of new chelating resin to metal ions were investigated. The main contents and conclusions are as follows:(1) A new TSC chelating resin was synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP) method. Glycidyl methacrylate (GMA) was grafted onto the surface of the chloromethyl polystyrene resin by SI-ATRP using the organic metal compound formed in the CuBr/2,2’-bipyridine (Bpy) system as catalyst at room temperature. The TSC chelating resin was synthesized by grafting thiosemicarbazide (TSC) on the surface of polyglycidyl methacrylate (PGMA) modified polystyrene resin. The chelating resin was characterized by means of elementary analysis and infrared spectrum analysis and scanning electron microscope, Characterization results is consistent with expected structure. The amount of TSC on the surface of polystyrene resin was calculated to be92.16mg/m2. The results of adsorption test showed that:the highest value of adsorption capacity of silver(Ⅰ) was298.17mg/g at pH3. Adsorption capacity of silver (Ⅰ) increased with increasing initial metal ion concentration and temperature. The kinetic experiments showed that:the experimental datas fitted well to second-order kinetic model. The thermodynamic experiments showed that the equilibrium adsorption data fitted well to Freundlich isotherms. The thermodynamic equilibrium functions were also determined.△G=-5.282kJ/mol,△H=175.38kJ/mol,△S=606.248J/(mol·K), so the adsorption was spontaneous, endothermic and entropy increasing.(2) A new DICY chelating resin was synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP) method. Glycidyl methacrylate (GMA) was grafted onto the surface of the chloromethyl polystyrene resin by SI-ATRP using the organic metal compound formed in the CuBr/2,2’-bipyridine (Bpy) system as catalyst at room temperature. The DICY chelating resin was synthesized by grafting Dicyandiamide (DICY) on the surface of polyglycidyl methacrylate (PGMA) modified polystyrene resin. The chelating resin was characterized by means of elementary analysis and infrared spectrum analysis, Characterization results is consistent with expected structure. The amount of DICY on the surface of polystyrene resin was calculated to be47.78mg/m2. The results of adsorption test showed that:the highest value of adsorption capacity of nickel(Ⅱ) was112.63mg/g at pH5. Adsorption capacity of nickel(Ⅱ) increased with increasing initial metal ion concentration and temperature. The kinetic experiments showed that:the experimental datas fitted well to second-order kinetic model. The thermodynamic experiments showed that the equilibrium adsorption data fitted well to both Langmuir and Freundlich isotherms. The thermodynamic equilibrium functions were also determined:△G=-6.407kJ/mol,△H=319.8kJ/mol, AS=1094.654J/(mol·K), so the adsorption was spontaneous, endothermic and entropy increasing.