Immobilization of cationic polyelectrolyte on polystyrene spheres and adsorption for model whitewater contaminants

Polystyrene (PS) spheres with cationic polyelectrolyte brushes were prepared by reversible addition-fragmentation chain transfer polymerization (RAFT) from cross-linked PS spheres. These PS spheres were subsequently modified by reaction with chloroacetyl chloride and S,S-Bis(α,α’-dimethyl-α”-acetic acid) trithiocarbonate to serve as macro chain transfer agents (macro-CTAs). Methacryloxyethyltrimethyl ammonium chloride (MAC) was then grafted from these macro-CTAs of PS spheres to obtain cationic PS spheres. FT-IR, 13 C-NMR, SEM, element analysis, and TGA techniques were applied to investigate and optimize the structure of PS spheres. The cationic PS spheres loading 1.35 mmol/g poly-MAC were used as absorbents for removal of polygalacturonic acid (PGA) and sodium ligninsulfonate (lignin-Na). Adsorption capacity of cationic PS spheres could reach 3 mg PGA/g and 24 mg lignin-Na/g, respectively. Moreover, adsorption isotherm data of PGA were described by Langmuir-Freundlich model, whereas lignin-Na conformed to Langmuir model. Kinetic studies suggested that dissolved substances (PGA and lignin-Na) could diffuse into the pores of cationic PS spheres. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42509.