Rheological Properties of Thermo-reversible Gels

From the stress relaxation data of various kinds of thermo-reversible gels obtained by means of a chainomatic balance relaxometer, it has been found that: 1) The modified time-temperature superposition principle which includes the vertical shift along the log Er(t) axis as well as along the log time axis can be successfully applied to the hydrogels of agar-agar and gelatin, and composite relaxation curves are obtained with good coincidence; 2) The activation energy Δ which is obtained from the τ1 vs. 1/T relation and which is regarded as the activation energy of the bond cleavage process at the junctions in the network is substantially equal to the value of the hydrogen bond in water and ethyl alcohol for the gels of the polyvinyl alcohol-glycerin-water system and for the hydrogels of agar-agar and gelatin; the value of Δ is, however, a little larger for the gels of the polyvinyl alcohol-Congo red-water system.