The complex of Sm2(o-NBA)6(PHEN)2 (o-NBA, o-Nitrobenzoate; PHEN, 1,10-phenanthroline) was prepar-ed and characterized by elemental analysis, IR and UV spectraoscopy. The thermal decomposition mechanism of Sm2(o-NBA)6(...The complex of Sm2(o-NBA)6(PHEN)2 (o-NBA, o-Nitrobenzoate; PHEN, 1,10-phenanthroline) was prepar-ed and characterized by elemental analysis, IR and UV spectraoscopy. The thermal decomposition mechanism of Sm2(o-NBA)6(PHEN)2 was studied under a static air atmosphere by TG-DTG. The thermal decomposition kinetics of the complex for the first stage was studied under non-isothermal condition. The most probable mechanism functions of the thermal decomposition reaction for the first stage are: G(α)=[-ln(1-α)]1/2, f(α)=2(1-α)[-ln(1-α)]1/2. The activation energy E for the first stage is 259.50 kJ·mol-1, the pre-exponential factor A is 36.19×1018 min-1. The lifetime equation at weight-loss of 10% was deduced as lnτ=-36.70+27 572.12/T by isothermal thermogravimetric analysis.展开更多
FT infrared spectrometer was used to obtain a series of infrared spectra at various temperatures of pentaerythritol(PE)、pentaglycerine(PG)、neopentylglycol(NPG) and their binary mixtures.The shifts of -OH absorption ...FT infrared spectrometer was used to obtain a series of infrared spectra at various temperatures of pentaerythritol(PE)、pentaglycerine(PG)、neopentylglycol(NPG) and their binary mixtures.The shifts of -OH absorption peak reveal the solid solid phase transition mechanisms and the connection of wave number shifts with temperature and enthalpies of phase transition.The solid solid phase transitions of the three polyols and their binary mixtures are known to transform from a low symmetric layered crystal structure to a highly symmetric face centered cubic structure.Experimental results support a mechanism which involves reversible breaking of nearest neighbor hydrogen resonance bonds in the molecular crystals at the transformation temperature.Infrared spectra show reversible increase in the wave number of the absorption peak of -OH groups with reversible breaking of the hydrogen bonds.This is in agreement with the experimental results of X ray diffraction and thermal analysis.展开更多
The thermal decomposition process of KAI(SO4)2’ 12H2O and its kinetics has been studied by TG-DTG. By Dollimore method, D3 is defined as the second step of thermal decomposition kinetic model and its kinetic equation...The thermal decomposition process of KAI(SO4)2’ 12H2O and its kinetics has been studied by TG-DTG. By Dollimore method, D3 is defined as the second step of thermal decomposition kinetic model and its kinetic equation is da/dT = (l /P) CT '(3/2(l - a)2/3[ 1- (l - a)1/3] - 1 ). At the same time, it has been found that the apparent activation energy E increases with the increases of fraction of conversion a and the absolute temperature T, and then it shows that a linear relationship with the temperature T has been obtained.展开更多
文摘The complex of Sm2(o-NBA)6(PHEN)2 (o-NBA, o-Nitrobenzoate; PHEN, 1,10-phenanthroline) was prepar-ed and characterized by elemental analysis, IR and UV spectraoscopy. The thermal decomposition mechanism of Sm2(o-NBA)6(PHEN)2 was studied under a static air atmosphere by TG-DTG. The thermal decomposition kinetics of the complex for the first stage was studied under non-isothermal condition. The most probable mechanism functions of the thermal decomposition reaction for the first stage are: G(α)=[-ln(1-α)]1/2, f(α)=2(1-α)[-ln(1-α)]1/2. The activation energy E for the first stage is 259.50 kJ·mol-1, the pre-exponential factor A is 36.19×1018 min-1. The lifetime equation at weight-loss of 10% was deduced as lnτ=-36.70+27 572.12/T by isothermal thermogravimetric analysis.
文摘FT infrared spectrometer was used to obtain a series of infrared spectra at various temperatures of pentaerythritol(PE)、pentaglycerine(PG)、neopentylglycol(NPG) and their binary mixtures.The shifts of -OH absorption peak reveal the solid solid phase transition mechanisms and the connection of wave number shifts with temperature and enthalpies of phase transition.The solid solid phase transitions of the three polyols and their binary mixtures are known to transform from a low symmetric layered crystal structure to a highly symmetric face centered cubic structure.Experimental results support a mechanism which involves reversible breaking of nearest neighbor hydrogen resonance bonds in the molecular crystals at the transformation temperature.Infrared spectra show reversible increase in the wave number of the absorption peak of -OH groups with reversible breaking of the hydrogen bonds.This is in agreement with the experimental results of X ray diffraction and thermal analysis.
文摘The thermal decomposition process of KAI(SO4)2’ 12H2O and its kinetics has been studied by TG-DTG. By Dollimore method, D3 is defined as the second step of thermal decomposition kinetic model and its kinetic equation is da/dT = (l /P) CT '(3/2(l - a)2/3[ 1- (l - a)1/3] - 1 ). At the same time, it has been found that the apparent activation energy E increases with the increases of fraction of conversion a and the absolute temperature T, and then it shows that a linear relationship with the temperature T has been obtained.
