A possible effect of quantum characteristics of vibrational dynamics on the conformational dynamics in polymers

Dielectric losses in poly(vinyl acetate) and poly(ethyleneterephthalate) polar polymers are measured in wide ranges of frequencies and temperatures. The temperature dependences of the frequency of activation transitions of two types, small-scale and conformational, are derived. For conformational transitions, it is revealed that the temperature dependence of their frequency exhibits nonlinear behavior (in Arrhenius coordinates); it determines the temperature dependence of barriers to transitions and the defreezing temperature of conformational dynamics (∼300 K for poly(vinyl acetate) and ∼370 K for poly(ethyleneterephthalate)). This temperature is found to be close to the temperatures of the quantum defreezing of the molecular dynamics of poly(vinyl acetate) and poly(ethyleneterephthalate) (∼300 and 400 K) according to IR spectroscopy data. It is assumed that a decrease in the barrier to the conformational transitions that provide defreezing of the conformational dynamics is caused by a decrease that occurs in the rigidity of polymer molecules owing to quantum defreezing of the vibrational molecular dynamics of the polymers.