Kinetic study of acrylamide radical polymerization initiated by the horseradish peroxidase-mediated system

The polymerization kinetics of acrylamide (AAM) in water initiated by a ternary enzymatic system of horseradish peroxidase (HRP)/H ₂O ₂/acetylacetone (ACAC) was investigated. Conversion-time plots were obtained by dilatometry under different conditions of reaction temperatures and initial concentrations of HRP, ACAC, H ₂O ₂, and AAM. The results showed that the effect of the initial concentration of ACAC on the inhibition period was significant. The inhibition period decreases with increasing the initial concentration of ACAC. The inhibition period can be even eliminated by the use of a comparatively large amount of ACAC. From the conversion-time plots, the polymerization rate equation was obtained. Some kinetic features were explained on the basis of analysis of the reaction mechanism.