| Based on the evolution of thiourea resins and their adsorption to metal ions, polymeric benzenedicarbonyl thiourea resins--PBDT were synthesized. Synthesis technology and their adsorption properties were studied in this paper.PBDT thiourea resins were synthesized by polymerization of disothiocyanadate and diamines. 1,3-/1,4-benzenecarbonyl diisothiocyanate were prepared by the solid-liquid phase transfer catalysis reaction of 1,4-benzendicarbonly dichloride and ammonium thiocyanate(NH4SCN), catalyzed by polyethylene glycol-400 (PEG-400); secondly, 1,3-/1,4-benzenecarbonyl diisothiocyanate polymerized with diamines to prepare PBDT resins. Yield of PBDT resins are as high as 84.5%-90.2% under 30℃, when molar ratio of diamines and 1,3-/1,4-benzenecarbonyl diisothiocyanate is 1:1. PBDT resins were characterized by IR, XRD, SEM, TG and so on.With batch method, the influence of adsorption duration, temperature, dosage of resins, acidities of metal ion solution, initial concentration of metals was studied. The adsorption process of PBDT1-2 and PBDT2-2 to Ni2+ reached equilibrium after 60 mins, the rate of resin adsorption was basically stable when the dosage of resins reached 0.30g. With the increases of acidities, adsorption rates increase firstly and decrease successively for Ni2+, adsorption rates increase with the increase of temperature, the initial concentration of metals.Adsorption kinetics, isotherm, thermodynamics were researched, and the adsorption mechanism of PBDT resin to Ni2+ was discussed. Liquid film spreading is the predominant step of the adsorption process; Isotherm adsorption process can be well described by Langmuir models, which indicates that the adsorption is a monolayer one; Enthalpy changeΔH of the process is plus, which demonstrated that adsorption process is endothermic. IR contrastive analysis before and after adsorption revealed that the Ni2+ ion was chelating with the resins to form a compound while adsorbing.
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