Sulfonated Styrene−Divinybenzene Resins: Optimizing Synthesis and Estimating Characteristics of the Base Copolymers and the Resins

Sulfonic Containing Polymer Bead Synthesized through Inverse Suspension Polymerization and Its Characteristics for Esterification Catalyst

The sulfonic containing polymer bead was synthesized using sodium p-styrenesulfonate (SSS) and N,N′-methylenebisacrylamide (MBA) through inverse suspension polymerization and evaluated as catalyst for esterification of of n-octanol and acrylic acid. The influence of some principal factors, such as combination dispersant, crosslink agent content, posttreatment methods, and porogen types, was investigated in detail. The results showed that the morphology and characteristics of polymer beads were controllable. The polymer beads with 20wt% crosslink agent showed the best catalysis ability achieving almost 96% esterification conversion at the first time and 80% after 5 cycles.

Facile fabrication of sodium styrene sulfonate-grafted ethylene-vinyl alcohol copolymer as adsorbent for ammonium removal from aqueous solution

An adsorbent EVOH-g-SSS(H) was successfully synthesized for ammonium removal by one-step grafting SSS onto EVOH particles directly using radiation-induced grafting technique followed by protonation. The effects of adsorbed dose and monomer concentration on grafting yield were investigated. The adsorption behaviors of the EVOH-g-SSS(H) towards ammonium ions (NH₄⁺) were discussed. The adsorption isotherm of NH₄⁺ was a followed Langmuir model with the maximum adsorption capacity of 22.53 mg/g at optimal pH 6.5. For comparison, adsorption kinetics towards NH₄⁺ removal by EVOH-g-SSS(H) and commercially available DIAION PK228 were studied. Both adsorbents were better obeyed pseudo-second-order mode. EVOH-g-SSS(H) for NH₄⁺ uptake was faster than PK228 and reached equilibrium within 5 min. Column experiment showed that the column adsorption capacity of EVOH-g-SSS(H) adsorbent was 9.69 mg/g-ad at SV 10 h^-1. The NH₄⁺ concentration in outlet solution can maintain at a very low level even SV was as high as 800 h^-1. The elution curve showed the EVOH-g-SSS(H) adsorbent can be regenerated using 1 M HCl. Besides, the removal percentage of NH₄⁺ can be 97% from actual groundwater within 1 min. Such high adsorption efficiency of EVOH-g-SSS(H) makes it to be employed as an adsorbent for NH₄⁺ removal in practical application.