DIELECTRIC-RELAXATION OF THE KOHLRAUSCH-TYPE IN AQUEOUS POLYMER-SOLUTION

Micro-Brownian motion of polymer chain in aqueous solution was clearly observed at first for poly(vinyl pyrrolidone) as a dielectric relaxation by a time domain reflectometry method which covers an extremely wide frequency region from 100 kHz-10 GHz. The dielectric response function observed is of the Kohlrausch-type as expected for the chain motion, phi(t)=exp[-(t/tau(l))beta l]. Concentration dependence of the relaxation time tau(l) at 25-degrees-C is given by log tau(l)=-9.77-1.35/(c(d)-2.07), where c(d) is the polymer concentration (g/cc), and that of the coupling parameter beta(l) is given by beta(l)=-0.182c(d)+0.662. These dependences are characteristic features of the relaxation caused by the chain motion.