Kinetic investigation of the dispersion polymerization of N,N′‐methylenebis(acrylamide) in the presence of various emulsifiers

The aqueous‐phase dispersion polymerization of N,N′w‐methylenebis(acrylamide) (MBA) in the presence of various additives was kinetically investigated at 50°C by conventional gravimetric and dilatometric methods. The rate of polymerization is found to be proportional to the concentration of sodium 1,2‐bis(2‐ethylhexyloxycarbonyl)ethanesulfonate (AOT) raised to the power of 0,42 (conc. of emulsifier <10−2) and to the conc. of ethylene glycol monooctylphenyl ether (TR) raised to the power of 0,23. On the other hand, it is independent of the conc. of poly(ethylene glycol) (PEG) and Tween 80 (TW). The rate of polymerization is proportional to the conc. of potassium peroxodisulfate (K2S2O8) raised to the power of 0,54 or 0,8 for systems with AOT or TW, respectively, and to the conc. of MBA raised to the power of 0,47 or 0,28 for the two respective systems. The effect of pH on the polymerization of MBA is assigned to the change of the decomposition rate of K2S2O8. The stabilization effect of the emulsifiers used decreases in the following order: AOT > TR ≈ PEG ≈ TW.