Heat Capacity and Standard Thermodynamic Functions of Triphenylantimony Dimethacrylate over the Temperature Range from (0 to 400) K

摘要

Heat capacities of triphenylantimony dimethacrylate Ph3Sb(O2CCMe=CH2)2 were measured by precision adiabatic vacuum calorimetry over the temperature range from T= (6 to 335) K and by differential scanning calorimetry over the temperature range from T= (300 to 470) K. The melting of the sample was observed within the above temperature range. The melting was accompanied by a compound decomposition. On the obtained data, the standard thermodynamic functions of molar heat capacity C_(pm)~° enthalpy H~°(T) - H~°(0), entropy S~°(T), and Gibbs energy G~°(T) - H~°(0) of Ph3Sb(O2CCMe=CH2)2 were calculated over the range from T = (0 to 400) K. The low-temperature (T < 50 K) heat capacity dependence was analyzed on the basis of Debye's heat capacity theory of solids and its multifractal model, so the characteristic temperatures and the fractal dimension were determined, and some conclusions about the structure topology were made. The standard entropy of formation at T - 298.15 K of Ph3Sb(O2CCMe=CH2)2(cr) was calculated.