Search

Polymeric matrices in the form of microspheres were obtained by copolymerization of the tetrafunctional monomers: 2,3-(2-hydroxy-3-methacryloyloxypropoxy)naphthalene (2,3-NAF.DM) or (bis[4(2-hydroxy-3-methacryloyloxypropoxy)phenyl]sulphide (BES.DM) with styrene (St). Next multistage modification which introduced the methylenethiol groups on the surface of copolymers was carried out. New materials were used in sorption processes to remove toxic heavy metal ions particularly Cd(II), Pb(II), Cu(II), Zn(II), and Ni(II) from aqueous solutions. The effects of the contact time on the sorption of the above-mentioned ions are presented. Sorption capacity depending on the type of monomers, modification, surface character, and porous structure of polymer was determined. The synthesized microspheres 2,3-NAF.DM-St-CH2SH and BES.DM-St-CH2SH indicate potential to adsorb heavy metal ions in the state and batch equilibrium systems. [ABSTRACT FROM PUBLISHER]

Synthesis and characterization of the new polymeric ion exchangers with thiol and sulfonyl hydroxide groups are presented. These new sorbents were also compared with polymeric microspheres possessing methylenethiol groups on the surface presented previously. The polymeric cation ion exchangers in the form of microspheres were obtained by the suspension-emulsion polymerization tetrafunctional monomer: 2,3-(2-hydroxy-3-methacryloyloxypropoxy)naphthalene (2,3-NAF.DM) with styrene (St). Next, multistage modification introducing sulfur-containing group (thiol or sulfonyl hydroxide or methylenethiol) on the surface of polymeric matrices was made. In order to obtain sulfonyl hydroxide derivatives the matrices were performed as follows: the parent microspheres were treated by H2SO4(Method I) or with the addition of oleum (Method II). The thiol groups were introduced in a two-stage reaction. In the first stage chlorosulfonation of parent microspheres in the presence of chlorosulfonic acid was carried out. Finally, the reduction of modified microspheres by using SnCl2·2H2O was conducted. The sulfur group content (elemental analysis, scanning electron microscope EDX SEM), thermal properties (thermogravimetric analysis), porous structure as well as the swelling characteristics of the functional beads were examined. The surface texture was also visualized by the AFM method. [ABSTRACT FROM PUBLISHER]