Thermodynamics of 1,4-diisocyanatobutane in the range from T → (0 to 360) K at standard pressure

Abstract

The temperature dependence of heat capacity of 1,4-diisocyanatobutane in crystalline and liquid states was determined by precision adiabatic vacuum calorimetry in the temperature range (8 to 360) K at standard pressure mainly with an uncertainty of ±0.2%. Thermodynamic characteristics of fusion, the first and the second cryoscopic constants, the isochoric heat capacity C v and its lattice C v,lat, and atomic at C v,at components were estimated. The data were used to calculate the standard thermodynamic functions C p , m ∘ / R , Δ ∘ T H m ∘ / R , Δ ∘ T S m ∘ / R and Φ m ∘ / R = Δ ∘ T S m ∘ / R - Δ ∘ T H m ∘ / TR (where R is the universal gas constant) over the range T → (0 to 360) K. The energy of combustion was measured at T = 298.15 K by the bomb calorimetry. The standard thermodynamic characteristics of formation, namely, the enthalpy Δ f H m ∘ , the entropy Δ f S m ∘ , the Gibbs function Δ f G m ∘ and ln K f ∘ of 1,4-diisocyanatobutane were evaluated at T = 298.15 K.