New crosslinked hydrogels derivatives of 2-hydroxyethyl methacrylate: Synthesis, modifications and properties

This paper presents the synthesis, physicochemical properties and modifications of 2-hydroxyethyl methacrylate copolymers. It describes the new 2-hydroxyethyl methacrylate hydrogels in the form of microbeads of different degrees of crosslinking (2, 5, 8, 10, 15 and 20% mol). As crosslinking monomers bis[4(2-hydroxy-3-methacryloyloxypropoxy) phenyl]-sulfide and ethylene glycol dimethacrylate were used. The new hydrogels were obtained by two alternative methods in a suspension copolymerisation procedure. The copolymers were modified with diethylenetriamine in an epoxide opening reaction. Thermal properties (differential scanning calorimetry, thermogravimetric analysis) and swelling characteristic in typical solvents of the obtained functional hydrogels were examined. The chemical structure of the copolymers before and after modification was confirmed by Fourier transform infrared spectroscopy and elemental analyses. Moreover, their sorptive properties in removal of Cu(II), Zn(II), Cd(II), and Pb(II) ions from aqueous solutions were also presented. The Langmuir and Freundlich isotherm models are used to describe the adsorption characteristics of the selected modified hydrogels.