GLASS-TRANSITION TEMPERATURE AND CRITICAL PROPERTIES

In a preceding paper it was shown that for high molecular weight polymers, the volume of the repeating unit at Tg is proportional to the total free space defined as Vc-V0 where Vc is the volume of the repeating unit at the critical temperature and V0 is the volume of the repeating unit at absolute zero. Here it will be demonstrated that this proportionality is also true for a host of low molecular weight liquids. In addition, an empirical method of estimating Tc for a high molecular weight polymer is proposed which provides values of Tc which are consistent with those for low molecular weight liquids. © 1979.