The kinetics of the polymerization of dimethyldiallylammonium chloride (DMDAAC) and acrylamide (AM) with different monomer molar ratios initiated by an ammonium persulfatesodium bisulfate redox complex in an aqueous solution were studied. The polymerization rate (Rp) equation, the activation energy (Ea), and the reactivity ratio were measured. The results show that when the nDMDAAC:nAM values were 1 : 9, 2 : 8, 3 : 7, 4 : 6, and 5 : 5, the copolymerization rate equation were Rp1 = k[M]2.61[IO]0.51[IR]0.52, Rp2 = k[M]2.70[IO]0.50[IR]0.53, Rp3 = k[M]2.73[IO]0.50[IR]0.56, Rp4 = k[M]2.77[IO]0.51[IR]0.59, and Rp5 = k[M]2.84[IO]0.51[IR]0.61 (where [M] is the total monomer concentration, [IO] is the oxidant concentration, and [IR] is the reductant concentration), respectively when the temperature was 45 degrees C. The Ea values were Ea1 = 79.10 kJ/mol, Ea2 = 81.39 kJ/mol, Ea3 = 85.15 kJ/mol, Ea4 = 88.88 kJ/mol, and Ea5 = 90.61 kJ/mol in the temperature range 3555 degrees C, respectively. The reactivity ratios of DMDAAC and AM were rDMDAAC = 0.14 and rAM = 6.11 when the temperature was 45 degrees C. The structure of PDA was characterized by Fourier transform infrared spectroscopy and 1H-NMR. The results of the kinetic parameters explained the differences in the copolymerization rate and intrinsic viscosity of PDA with different cationicities. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012