Thermofluctuational nature

In Fig. 1.4, the dependences v j(7) for polycarbonate (PC) and polyarylate (PAr) are adduced. These dependences show v, reduction at T growth, that assumes local order regions (clusters) thermofluctuational nature. Besides, on the indicated dependences two characteristic temperatures are found easily. The first from them, glass transition temperature F, defines clusters fixll decay (see also Fig. 1.1), the second corresponds to the fold on curves v j(7) and settles down on about 50 K lower T. ... 

There are some problems of interest in the description of the free volume of polymers. As has already been mentioned, both fluctuation free volume and clusters have a thermofluctuational nature. It is obvious that the energy of thermal fluctuations can be expressed as kT (where k is Boltzmann s constant, T is temperature), while microvoid formation energy is equal to [80] ... 

The TSM for elementary processes in condensed systems [58] employs the traditional tenets of Eyring s model [20,23], although it follows from the nature of the condensed state that the driving force of the process is ensured by thermofluctuation excitations of the medium, and not by the translational motion of the particles. In the transition state, an AC reacts with the neighboring particles. The parameter of their interaction - differs from the parameter of interaction between the initial reactant i which the AC is formed from and the neighboring particle j. 

Vettegren, V. I. (1984). About Physical Nature of Polymers Fracture Thermofluctuation Mechanism. Fizika Tverdogo Tela, 26,1699-1704. 

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