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 T_g is proportional to the total free space defined as V_c?V₀ where V_c 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 T_c for a high molecular weight polymer is proposed which provides values of T_c which are consistent with those for low molecular weight liquids.