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Indexed by:期刊论文

Date of Publication:2010-01-01

Journal:JOURNAL OF CHEMICAL AND ENGINEERING DATA

Included Journals:SCIE、EI

Volume:55

Issue:1

Page Number:119-124

ISSN No.:0021-9568

Abstract:The low-temperature heat capacity C(p,m) of D-mannitol was measured in the temperature range from (80 to 390) K by means of a fully automated adiabatic calorimeter. The dependence of heat capacity on the temperature was fitted to a polynomial equation with the least-squares method. The thermodynamic functions (H(T) - H(298.15) (K)) and (S(T) - S(298.15) (K)) were derived from the heat capacity data ill the temperature range of (80 to 390) K with an interval of 5 K. The melting temperature, molar enthalpy, and entropy of fusion were determined to be (437.25 +/- 0.12) K, (54.69 +/- 1.64) kJ.mol(-1), and (125.08 +/- 3.75) J.K(-1).mol(-1) by DSC measurements. The thermal stability and nonisothermal thermal decomposition kinetics of the compound were studied by the TG-DTG technique Under atmospheric pressure and flowing nitrogen gas conditions. The thermal decomposition process had one mass loss stage, and the apparent activation energy E(a) was obtained to be (120.61 +/- 1.85) kJ.mol(-1) by the Kissinger, Friedman, and Flynn-Wall-Ozawa methods. The Malek method Was used to identify the most probable kinetic model SB(m, n). The kinetics model function and the pre-exponential factor A were expressed to be: f(alpha) = alpha(0.306)(1 - alpha)(0.381); In A = 17.88, respectively.