PREPARATION AND CHARACTERIZATION OF POLYACRYLAMIDE IN CATIONIC MICROEMULSION

The polymerization of acrylamide in a water/oil cationic microemulsion initiated with a water-soluble radical initiator, potassium persulfat e (KPS), was investigated. The kinetics of microemulsion polymerizatio n clearly shows a two-stage process; when the initiator is dissolved i n a monomer solution before the emulsification, the reaction rate is h igher than it would be if added after the emulsification. The activati on energy of the polymerization is affected by the cosurfactant. Infor mation about the microstructures of polyacrylamides is derived from X- ray diffraction, DSC, FTIR, and laser-Raman studies. The results of th e studies suggest that the orientation behavior of microemulsion polym erization increases the crystallinity of polyacrylamide and the polar group (-NH2) is coiled in the inner part of the polymer particles comp ared to solution and water/oil emulsion polymerizations. (C) 1998 John Wiley & Sons, Inc.