The thermal decomposition kinetics of dehydroabietic acid in static state air was investigated by TG/DTA/DSC techniques with various heating rates of 5,10,15 and 20 K·min-1.TG/DTA curves showed that decomposition...The thermal decomposition kinetics of dehydroabietic acid in static state air was investigated by TG/DTA/DSC techniques with various heating rates of 5,10,15 and 20 K·min-1.TG/DTA curves showed that decomposition proceeded through a well-defined step in air.The melting point,molar enthalpy and entropy of fusion of dehydroabietic acid were determined as 445.05 K,19.74 kJ·mol-1 and 44.35 J·mol-1·K-1,by differential scanning calorimetry(DSC).The non-isothermal kinetics parameters were analyzed by means of the Kissinger and Flynn-Wall-Ozawa methods,and the thermal decomposition mechanism of dehydroabietic acid was also studied with the Satava-Sestak method.The results showed that the thermal decomposition mechanism of dehydroabietic acid in air was controlled by interface reaction R3,and the apparent activation energy and pre-exponential factor were 107.89 kJ·mol-1 and 9.33×108 s-1,respectively.展开更多
The title complex, formulated as Co（tda）（5-mphen）（H2O）（H2tda=thiodiglycolic acid, 5-mphen= 5-methyl-1,10-phenanthroline）, was synthesized and characterized by elemental analysis, IR spectroscopy, X-ray single ...The title complex, formulated as Co（tda）（5-mphen）（H2O）（H2tda=thiodiglycolic acid, 5-mphen= 5-methyl-1,10-phenanthroline）, was synthesized and characterized by elemental analysis, IR spectroscopy, X-ray single crystal diffraction, and TG-DTG techniques. The complex crystallized in monoclinic space group C2/c, with parameters of a=1.8142（2） nm, b=0.78251（9） nm, c=2.4624（3） nm,β=93.809（2）°, V=3.4880（7） nm^3, Z=8, Dc=1.579 g/cm^3, the final R indices[1〉2σ（1）] are R1=0.0469, wR2=0.1021, R indices for all data are R1=0.0835, wR2=0.1169. The central Co^2＋ cation is coordinated in a distorted octahedral geometry with the ligand tda, 5-mphen, and water molecule. The coordination complex possesses a three-dimensional framework by means of hydrogen bonds and π-π stacking interactions. According to TG-DTG curves, the possible thermal decomposition mechanisms, the possible kinetic parameters, and equation of dehydration stage of the complex are obtained, that is, Ea=110.98 kJ/mol, lg（A/s^-1）=8.554, da/dT= 10^8.5546/β.3（1-α）[-1n（1-α）]^2/3.exp（-13349/T）, respectively.展开更多
文摘The thermal decomposition kinetics of dehydroabietic acid in static state air was investigated by TG/DTA/DSC techniques with various heating rates of 5,10,15 and 20 K·min-1.TG/DTA curves showed that decomposition proceeded through a well-defined step in air.The melting point,molar enthalpy and entropy of fusion of dehydroabietic acid were determined as 445.05 K,19.74 kJ·mol-1 and 44.35 J·mol-1·K-1,by differential scanning calorimetry(DSC).The non-isothermal kinetics parameters were analyzed by means of the Kissinger and Flynn-Wall-Ozawa methods,and the thermal decomposition mechanism of dehydroabietic acid was also studied with the Satava-Sestak method.The results showed that the thermal decomposition mechanism of dehydroabietic acid in air was controlled by interface reaction R3,and the apparent activation energy and pre-exponential factor were 107.89 kJ·mol-1 and 9.33×108 s-1,respectively.
基金Supported by the National Natrual Science Foundation of China(No.20771089)
文摘The title complex, formulated as Co（tda）（5-mphen）（H2O）（H2tda=thiodiglycolic acid, 5-mphen= 5-methyl-1,10-phenanthroline）, was synthesized and characterized by elemental analysis, IR spectroscopy, X-ray single crystal diffraction, and TG-DTG techniques. The complex crystallized in monoclinic space group C2/c, with parameters of a=1.8142（2） nm, b=0.78251（9） nm, c=2.4624（3） nm,β=93.809（2）°, V=3.4880（7） nm^3, Z=8, Dc=1.579 g/cm^3, the final R indices[1〉2σ（1）] are R1=0.0469, wR2=0.1021, R indices for all data are R1=0.0835, wR2=0.1169. The central Co^2＋ cation is coordinated in a distorted octahedral geometry with the ligand tda, 5-mphen, and water molecule. The coordination complex possesses a three-dimensional framework by means of hydrogen bonds and π-π stacking interactions. According to TG-DTG curves, the possible thermal decomposition mechanisms, the possible kinetic parameters, and equation of dehydration stage of the complex are obtained, that is, Ea=110.98 kJ/mol, lg（A/s^-1）=8.554, da/dT= 10^8.5546/β.3（1-α）[-1n（1-α）]^2/3.exp（-13349/T）, respectively.
