Scaling limits of the glass transition in poly(vinyl chloride)

Within a scaling concept of glass transition interval of the logarithm of shear modulus indicates the scaling region, the different reduced volumes of which are mapped into a logarithm frequency‐temperature‐plot side by side and can be described by a set of WLF curves with the same asymptotes. Different signals at the glass transition from dynamic, thermic, and nuclear magnetic resonance (NMR) experiments are measured in a suspension poly(vinyl chloride) sample in an overall frequency diapason from 10 −4 to 10 +8 Hz. Neglecting any reduction of signal height a general master curve diagram for all signals is sketched. NMR signals roughly correspond to the lower and thermic bulk signals correspond to the upper scaling limit, the latter is given by cooperatively rearranging regions with dimensions of some nm. The volumes at the both limits as functions of temperature and the mean shear angle fluctuation are estimated. The β relaxation reaches the lower scaling limit of the glass transition at a temperature of (150 ± 10)°C and at a frequency of 10( 7,3 ± 0,5 ) Hz. The relationships between both relaxations are discussed.