THE THERMAL ENTROPY CONCEPT AND THE T-G TRANSITION

According to the present knowledge of polymer physics, the explanation of the T-g transition is based upon the configurational Flory-di Marz io-Adams approach in the overwhelming majority of cases. The majority of papers regarding the T-g transition have been presented along these lines. These papers used a different definition of thermal expansion coefficient from that used in solid state physics. The changes in c(p) values at T-g were related only to the changes in configurational ent ropy. In our approach the changes in thermal, anharmonic or wobbling t ypes of motion, contributing to the thermal entropy term, have been ta ken into account and these changes quantitatively result in stepwise v ariations in the ''alpha'' and ''c(p)'' values. The new theory yields new definitions of alpha and c(p), consistent with the definitions use d in solid state physics, while the configurational approach of Flory- di Marzio-Adams can be taken as a complementary and enriching addition to our theory.