Synthesis and characterization of a new fast swelling poly(EPMA-co-METAC) as superabsorbent polymer for anionic dye absorbent

Abstract

A novel superabsorbent polymer poly(2,3-epoxypropyl methacrylate-co-2-(methacryloyloxy)ethyl trimethyl ammonium chloride), p(EPMA-co-METAC), was prepared simply by free radical aqueous copolymerization reaction of 2,3-epoxypropyl methacrylate (EPMA) and 2-(methacryloyloxy)ethyl trimethyl ammonium chloride (METAC) using N,N′-methylenebisacrylamide (MBA) as a cross-linking agent and ammonium persulfate (APS) as a free radical initiator. The chemical structures of hydrogel were confirmed by FTIR and elemental analysis. The swelling behavior of the hydrogel samples was investigated under different experimental conditions such as time, pH, ionic strength and different media. In the second part of this study, the superabsorbent hydrogels were tested for the removal of an anionic dye, i.e., Coomassie Brilliant Blue G-250 (CBB), a molecule having a marked amphiphilic character, from aqueous environment. Finally, isotherm adsorption data of dye on hydrogels were modeled according to Langmuir and Freundlich isotherm models. The results revealed that the experimental data was correlated by both of them. Also, the kinetic parameters for the adsorption process of the dye were investigated based on the different kinetic models such as pseudo-first-order and second-order models and the adsorption kinetics followed well the pseudo-second-order model. Novel superabsorbent polymer samples also show good anionic dye absorbency and excellent swelling ability. As a result, p(EPMA-co-METAC) hydrogel appeared to be suitable for the removal of CBB from aqueous solutions.