| Abstract: | Water-in-Oil (W/O) and Oil-in-Water (O/W) type water absorbent polymer emulsions were studied using two different polymerization methods. W/O type water absorbent polymer emulsions were prepared by the inverse emulsion polymerization of ammonium acrylate (AA), the quaternized salt of dimethyl-aminoethyl methacrylate (DMQ) and acrylamide (AM) with N,N-methylene-bisacrylamide (MBA) as a crosslinker. A pH sensitive water absorbent polymer emulsion was prepared by the conventional emulsion polymerization of diethyl-aminoethyl methacrylate (DEAEMA) with ethylene glycol dimethacrylate (EGDMA) as a crosslinker. It was confirmed that the water absorption capacity of crosslinked polymers in inverse emulsion was controlled by crosslink density and dissociative charge density, and the crosslinked polyDEAEMA particles had a phase transition property of swelling and shrinking with pH. The dispersions of these water swollen crosslinked polymer particles exhibited an increase in viscosity and thixotropic fluidity. |
