Effect of Chemical Structure of Amorphous Polymers on Heat Capacity Difference at Glass Transition Temperature

T. Hatakeyama and H. Hatakeyama
[Thermochimica Acta., Vol. 267, pp. 249-257, 1995]

The heat capacity of 21 kinds of glassy polymers, mainly synthesized in our laboratory, was measured by differential scanning calorimetry. Glass transition temperature (T_g) and the heat capacity difference between the molten state and the glassy state (DeltaC_p) at T_g were evaluated. A linear relationship was obtained between DeltaC_p and T_g for almost all glassy polymers including engineering plastics, in a temperature range from 230 to 520 K, expect for those having large side chains and/or inter-molecular hydrogen bondings. It was suggested that configurational entropic factors must be taken into consideration for analyzing glass transition.