Kinetics of emulsion copolymerization of (2-methacryloyloxyethyl) trimethyl ammonium chloride and acrylamide with gamma rays

Inverse emulsion copolymerization of (2-methacryloyloxyethyl) trimethyl ammonium chloride with acrylamide has been studied with gamma ray dilatometrically. Aqueous monomer solutions were emulsified in kerosene with a blend of two surfactants (Span80 and OP10). The gel effect is evident from the increase of the molecular weight with conversion and also from the percentage conversion versus time curves. Monomer reactivity ratios have been derived as r(AM) = 0.23 and r(DMC) = 1.40 at pH 6.8. Initial emulsions and final inverse latexes displayed the same broad size distribution. The effects of dose rate, concentration and composition of the monomer, emulsifier concentration, etc. on polymerization rate and intrinsic viscosity of polymer have been examined. The rate of polymerization (R(p)) can be represented by R(p)cc D^0.87[M]^1.37[E]^0.53. The overall activation energy for the rate of polymerization is 16.9 kJ/mol (32-55°C). Based on these experimental results, some aspects of the polymerization mechanism are discussed.