PULSE RADIOLYSIS OF POLY(ETHYLENE OXIDE) IN AQUEOUS SOLUTION. Ⅱ. DECAY OF MACRORADICALS

摘要

Pulse radiolysis studies on the decay of macroradicals derived from poly(ethylene oxide) in deaerated aqueous solution have shown that this process does not follow classical second-order kinetics. This is attributed to the nature of the dominating reaction, i.e. intramolecular recombination. The rate of decay depends mainly on the average initial number of radicals formed on one chain (Z_(R~O)). It is shown that the decay may be well described with the non-homogeneous kinetics with time-dependent rate constant in the form k = B t~(α-1). The influence of polymer concentration, molecular weight and Z_(R~O) on the parameter α (a measure of non-homogeneity) is discussed.