Effect of Potassium Methacrylate Content on Synthesis, Swelling, and Diffusion Characteristics of Acrylamide/Potassium Methacrylate Hydrogels

Abstract

ABSTRACT Hydrogels based on acrylamide (AAM) and potassium methacrylate (KMA) were synthesized by simultaneous free radical polymerization in aqueous solution using the redox initiator ammonium persulfate (APS) and N,N,N′N′-tetramethylethylenediamine (TMEDA) at room temperature. Eight different compositions of KMA hydrogels were prepared at a fixed concentration of N,N′,-methylenebisacrylamide (MBA) or diallyl phthalate (DP) as crosslinking agents. For all the AAM-KMA hydrogels, the percentage of swelling, swelling kinetics, and diffusion characteristics were investigated. It was found that higher swelling percentage values were obtained for hydrogels crosslinked with DP than for the conventional crosslinker MBA. The de-swelling characteristics of hydrogels were also studied in detail. The power law relationship of hydrogels was evaluated in saline solutions. Hydrogels formation was confirmed by IR spectroscopy. The thermal characteristics of these hydrogels were studied by using differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA) and revealed that MBA crosslinked AAM-KMA hydrogels show higher glass transition temperature (Tg) as well as higher decomposition temperatures (Td) than DP crosslinked AAM-KMA hydrogels. It is further confirmed from the studies that the DP crosslinked hydrogels have good swelling as well as de-swelling and salinity characteristics.