SYNTHESIS AND STUDY OF A COMPLEXING SORBENT, BASED ON UREA, FORMALDEHYDE AND AMINOACETIC ACID, USING IR SPECTROSCOPYAND SCANNING ELECTRON MICROSCOPE

Abstract

The article presents the formula of the polyampholyte, synthesized by us -an ion-exchange sorbent (UFA), obtained by the reaction of polycondensation of urea, formaldehyde and aminoace-tic acid. The effect of pHmedium and reaction temperature on the molecular weight of the resulting polymer product was studied. The conditions for its synthesis are compared with the conditions for obtaining previously studied ion-exchange polyampholytes of the same type. The IR spectra of pol-yampholyte complexes with some d-elements: copper, nickel, zinc, cobalt and cadmium ions were registered and studied for the first time. These spectra are compared with the spectra of the poly-ampholyte itself, the ligand. It has been established that the synthesized sorbent contains intra and intermolecular hydrogen bonds of hydroxyl groups, methylene fragments -CH2-, carbonyl groups -C=O both in the ring and in the main chain, vibrations of bound OH groups. The presence of amide nitrogen in the polymer chain was shown. Based on the IR spectra, a scheme is presented for the synthesis of polyampholyte by polycondensation of the initial reagents: formaldehyde, urea (carbamide) and aminoacetic acid (glycine). Some physicochemical properties and results of ele-mental analysis of the coordination compounds of the resulting polyampholyte with five d-metal ions (Cu(II), Zn(II), Ni(II), Co(II), Cd(II)) are presented. Based on the analysis of the IR spectra of the complexes and their elemental analysis, a general structural formula of MFA complex com-pounds with the indicated ions was suggested. The surface structure of the resulting polyampholyte was studied by scanning electron microscopy (SEM analysis). The images obtained by this method indicate that this ion exchanger has a very good high sorption capacity or the ability to absorb various metal ions.