THE ROLE OF CHAIN CONFORMATION IN THE THEORY OF GLASSES .2. ENTHALPY RELAXATION

The author has incorporated the role of the conformational energies of polymer chains in the kinetic theory of glasses by extending the equilibrium analysis developed previously. Under the cooperative constraints of hole distributions, a large number of conformational energy states are also introduced for the purpose of analyzing the nonequilibrium behavior. The theory shows how the kinetics of holes and bond rotations affect the enthalpy relaxation. The calculation reveals that the conformational activation energy is between 1 and 2 orders of magnitude lower than the hole activation energy. As a result, the enthalpy relaxes much faster than the volume at short times but approaches the same relaxation rate of volume at long times.