DSC studies on synthesis of superabsorbent hydrogels

Reaction scheme of acrylic-based superabsorbing polymers was monitored by a differential scanning calorimeter. Differential scanning calorimetry (DSC) was used to study the heat effects during the polymer synthesis in DSC pan as a micro-scale reactor. Two distinct observations, i.e. inhibition period (IP) and onset of gel formation were recorded during polymerization. The effect of reaction temperature and initiator (K2S2O8) concentration was assessed on these general observations. It was found that unrestricted access of the reaction mixture to oxygen and unrestricted loss of water could complicate the polymerization behavior of sodium acrylate in aqueous system. A conceptual kinetic approach was followed to describe the complex process. Finally, DSC observations were compared with their corresponding bench-scale figures.