The T _ß , T _g , and T _ll “Transitions”: Are These the Manifestation of a Unique Relaxation Process?

Abstract

It was suggested in an earlier communication¹ that the T _ll relaxational process started to exhibit its thermal existence in the pre-T _g (T<T _g ) temperature region, and that this relaxation peak, usually designated at T _ß ² was not only the precursor of the T _g peak, but the true onset of the T _ll transition. We have recently presented a new theory of nonequilibrium kinetics³ which can be applied to the description of the weak force field (van der Waals type) of interaction between the mers belonging to the macromolecules, not necessarily located on the same single chains. The new theory allows a network structure for the total free energy due to the thermal and mechanical past history. The network is called EKNET, the Energetic Kinetic Network, to specify the energetic and kinetic constraints responsible for its very existence. The T _ll and T _ß relaxations naturally arise from the network structure of the free energy and from the nonequilibrium statistics which govern its instability over temperature and time. T _ll is apparently the temperature for the collapse of the EKNET structure of the weak force field.³ T _ß is the low temperature manifestation of the existence of the EKNET. In simplistic terms, the reason for T _ll to show up at T _ß , i.e., at a temperature below T _g , although it is generated by the T _g kinetics, is that its activation energy is much lower than that of T _g .