On the nature of the maximum gelation temperature in polymer gels

A theoretical framework is provided to explain the maximum gelation temperature in thermoreversible gelatin gels. Arrenhius plots of the inverse of the induction time of gelation versus the reciprocal of the setting temperature were linear for the different initial sol concentrations studied. Moreover, when extrapolated to higher temperatures, these lines intersected at a critical temperature. In this work, we show how this critical temperature corresponds to the temperature at which the polymer sol is in equilibrium with its activated state for a gelation reaction. We define this critical temperature as the maximum gelation temperature.