Study On Preparation And Application Of Iminodiacetic Acid Chelate Fiber

A new type of ion exchange fiber containing iminodiacetic groups for the removal ofCu2+was prepared from chloramethylated styrene grafted polypropylene fiber reacted withTetraethylenepentamine and chloroacetic acid. For amination and carboxymethylation，several factors such as solution temperature, reaction time, bath ratio(solvent:solid,V:m)were examined on the productive rate by using orthogonal test. The structure andthermal properties of the iminodiacetic chelate fiber were also characterized by elementaryanalysis (EA), Fourier Transform Infrared Spectra (FT-IR), Scanning Electron Microscopy(SEM), Energy Dispersive Spectrometer (EDS), Thermogravimetry (TG).The optimal synthesis conditions were achieved by using batch adsorptionexperiments. In the process of preparing styrene grafted polypropylene fiber, the optimumexperimental conditions were as follows: reaction time6hours, reaction temperature80℃,bath ratio50:1, the volume of Tetraethylenepentamine was15mL, while in the process ofpreparing iminodiacetic styrene grafted polypropylene fiber, the optimum experimentalconditions were reaction time6hours, reaction temperature70℃, bath ratio30:1, theamount of chloroacetic acid was2grams.The functional groups of fibers were investigated by EA and FT-IR. In addition, thesurface morphology of the fiber was examined by SEM, and the thermal stability wasresearched by TG. The elementary analysis shows that Cl was disappeared, the content of Nis7.28%and the content of O was less than that of amino ion exchange fiber in theiminodiacetic chelate fiber. The FT-IR spectrum indicates that there are stretching vibrationabsorption of O-H、N-H、C-N、C=O in the iminodiacetic chelate fiber which furtherconfirms the synthesis path. The scanning electron microscopy points out that syntheticreaction and adsorption were both occurred on the surface of fibers and the TG curvesshowed that the iminodiacetic fiber has a very good thermal stability.The results of static adsorption experiments showed that the process of Cu2+adsorptedto iminodiacetic fiber was rapid, and the highest binding capacities of the fibrous sorbentfor Cu2+was73.4mg·g-1. The selectivity of iminodiacetic fiber for Cu2+and Ni2+was investigated. The results showed that the fiber had a larger adsorption capacity for Cu2+. Itcould separate them thoroughly in the solution, which layed the foundation for industrialwastewater treatment. Adsorption isotherms at various temperatures were obtained.Langmuir model were adopted and the equilibrium data could fit well with Langmuirisotherm. The data of thermodynamic parameters suggested that the adsorption of Cu2+onIDACF was a spontaneous, entropy-driven process.