Thermodynamics of syndiotactic polystyrene in the range 0-600 K

The thermodynamic properties of syndiotactic polystyrene in the range 7-610 K were studied by the methods of adiabatic vacuum and dynamic calorimetry. The heat capacity C(p)degrees of a polymer sample precipitated from soluti on, melted, subsequently cooled to T < T(g)degrees, and annealed at differe nt temperatures was measured as a function of temperature. Various physical transformations of the polymer upon its heating or cooling were revealed a nd their thermodynamic characteristics were determined. From the obtained e xperimental data, the temperature dependences of the heat capacity of syndi otactic polystyrene in the amorphous and crystalline states, the thermodyna mic parameters of the glass transition and the glassy state, and the thermo dynamic characteristics of melting were determined and the thermodynamic fu nctions C(p)degrees (T), H degrees (T) - H degrees (0), S degrees (T), and G degrees (T) - H degrees (0) for these physical states of the polymer in t he range 0-600 K were calculated.