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Xue-jie Wang - One of the best experts on this subject based on the ideXlab platform.
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Thermal Decomposition mechanism of piroxicam
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Piroxicam (PRX) is a nonsteroidal anti-inflammatory drug. The Thermal Decomposition process of PRX was investigated with thermogravimetry and differential scanning calorimetry. The gaseous products generated by Thermal Decomposition were characterized with thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The residues of the Thermal Decomposition at various temperatures were identified with infrared spectroscopy. The molecular bond orders were calculated using an ab initio method from the GAMESS program of quantum chemistry. The mechanism of Thermal Decomposition for PRX was discussed. The results indicated that the Thermal Decomposition of PRX is a two-stage process with the initial temperature of 198 °C either in nitrogen or air atmospheres. The Thermal Decompositions of the first stage in two atmospheres are the same process. The main part of the molecule, including sulfamide, amide, benzene ring and pyridine ring, decompose simultaneously and to form gasifiable small molecules and carbonaceous residue in the first stage. The second stage in nitrogen is a slow Thermal pyrolysis process of carbonaceous residue. The forepart of the second stage in air is a slow Thermal pyrolysis process as like as in nitrogen, and the later period of the second stage is an oxidation (combustion) reaction process of carbonaceous residue. PRX is stable under ambient temperature and air atmosphere, and it can be preserved for long-term storage under ambient temperature and in air atmosphere.
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The Thermal Decomposition mechanism of irbesartan
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Abstract Irbesartan (IBS) is an inhibitor of angiotensin II receptor. In order to study the Thermal stability and the Thermal Decomposition mechanism of IBS, the Thermal Decomposition processes of IBS in nitrogen and in air atmospheres were studied by means of thermogravimetry (TG) and differential scanning calorimetry (DSC), the evolved gaseous products from Thermal Decomposition were identified with thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR), and the residues of Thermal Decomposition at various temperatures were analyzed with infrared spectra, high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC–MS). The molecular bond orders were calculated by GAMESS program of quantum chemistry, and the Thermal Decomposition mechanism of IBS was discussed. The results indicated that the Thermal Decomposition of IBS is a three-stage process and the initial temperatures of the Decomposition are 204.7 and 201.0 °C in nitrogen and in air, respectively. The initial step of the Decomposition is the partial Decomposition of imidazolone and tetrazol sections. The Thermal stability of IBS is quite good in the routine temperature.
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Thermal Decomposition mechanism and kinetics of gemcitabine
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Abstract Gemcitabine (GTB) is a nucleoside drug used in chemotherapy for various carcinomas. In order to know why does GTB have good Thermal stability, and to further understand the relationship between Thermal stability and molecular structure. The Thermal Decomposition of GTB was measured with various Thermal analytical techniques, the gaseous products and the residues of Thermal Decomposition were determined and identified. The molecular bond orders were calculated. The Thermal Decomposition mechanism of GTB was discussed. The Thermal Decomposition kinetics and the prospective lifetime of GTB were studied using the ATSM method. The results indicated that two strong electronegative fluorine atoms on furan ring make the strong charge-transfer (CT) structure to be formed, this strong CT structure remarkably enhance the N-glycosidic bond and the weakest bond, and lead to higher Thermal stability and distinctive Thermal Decomposition mechanism. The Thermal Decomposition of GTB is a three-stage process. The initial step of Decomposition is likely due to the loss of a furan ring. Most of GTB decompose and carbonizes directly to form insoluble substance and small molecules and just part of GTB decompose by way of cytosine stage. The initial Decomposition temperature in either nitrogen or air is 235 °C. For Decomposition in nitrogen, the apparent activation energy Ea and pre-exponential factor A for the initial Thermal Decomposition are 123.4 kJ mol−1 and 3.80 × 1010 min−1, respectively. For Decomposition in air, the corresponding Ea and A are 126.3 kJ mol−1 and 7.94 × 1010 min−1, respectively. GTB has very good Thermal stability under routine temperature and dry air atmosphere.
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The Thermal Decomposition mechanism and kinetics of tenoxicam
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Abstract Tenoxicam (TNX) is a non-steroidal anti-inflammatory drug. Its Thermal Decomposition processes were studied with thermogravimetry and differential Thermal analysis. The produced gaseous products and residues during Decomposition were detected and characterized using Fourier transform infrared spectroscopy. Combining with the molecular bond order distribution obtained from the quantum chemistry calculation, the Thermal Decomposition mechanism of TNX has been speculated. The kinetic parameters for Thermal Decomposition, such as activation energy Eα and the pre-exponential factor A, were obtained using the ATSM E1641 method. The prospective lifetime of TNX was estimated using the ATSM E1877 method. The results indicated that the Thermal Decomposition of TNX is a three-stage process. During the first stage of Thermal Decomposition, the main part of the molecule, including sulfamide, thiophene and amide, decompose simultaneously, and to form gasifiable small molecules and carbonized residues. The initial Decomposition temperature in either nitrogen or air is about 204°C. For Decomposition in nitrogen, the Eα and A for the initial Thermal Decomposition are 174.8 kJ mol−1 and 2.512 × 1017 min−1, respectively. For Decomposition in air, the corresponding Eα and A are 179.4 kJ mol−1 and 7.943 × 1017 min−1, respectively. The TNX has good Thermal stability under routine temperature.
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Study on the Thermal Decomposition of famciclovir
Journal of Thermal Analysis and Calorimetry, 2017Co-Authors: Jin-Zong You, Xue-jie WangAbstract:The Thermal Decomposition of famciclovir (FCV) was measured with thermogravimetry, differential scanning calorimetry, and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The IR spectra, high-performance liquid chromatography, and liquid chromatography–mass spectrometry of FCV and the residues of its Thermal Decomposition at various temperatures were determined. The molecular bond orders were calculated using an ab initio method from the GAMESS program of quantum chemistry. The mechanism of Thermal Decomposition for FCV was discussed. The kinetic parameters for Thermal Decomposition such as activation energy E a and the pre-exponential factor A were obtained using the Ozawa method. The prospective lifetime of FCV was estimated using the Dakin equation. The results indicated that the Thermal Decomposition of FCV is a two-step process. The initial Decomposition temperature in either nitrogen or air is about 205 °C. The Decomposition of FCV does not go through 2-amino-purine stage, 2-amino-purine, and alkane chain segment both decompose simultaneously during the first stage. For Decomposition in nitrogen, the E a and A for the initial Thermal Decomposition are 107.8 kJ mol−1 and 2.19 × 109 min−1, respectively. For Decomposition in air, the corresponding E a and A are 96.4 kJ mol−1 and 1.45 × 108 min−1, respectively. The FCV has good Thermal stability under routine temperature.
Jin-Zong You - One of the best experts on this subject based on the ideXlab platform.
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Thermal Decomposition mechanism of piroxicam
Journal of Thermal Analysis and Calorimetry, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Piroxicam (PRX) is a nonsteroidal anti-inflammatory drug. The Thermal Decomposition process of PRX was investigated with thermogravimetry and differential scanning calorimetry. The gaseous products generated by Thermal Decomposition were characterized with thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The residues of the Thermal Decomposition at various temperatures were identified with infrared spectroscopy. The molecular bond orders were calculated using an ab initio method from the GAMESS program of quantum chemistry. The mechanism of Thermal Decomposition for PRX was discussed. The results indicated that the Thermal Decomposition of PRX is a two-stage process with the initial temperature of 198 °C either in nitrogen or air atmospheres. The Thermal Decompositions of the first stage in two atmospheres are the same process. The main part of the molecule, including sulfamide, amide, benzene ring and pyridine ring, decompose simultaneously and to form gasifiable small molecules and carbonaceous residue in the first stage. The second stage in nitrogen is a slow Thermal pyrolysis process of carbonaceous residue. The forepart of the second stage in air is a slow Thermal pyrolysis process as like as in nitrogen, and the later period of the second stage is an oxidation (combustion) reaction process of carbonaceous residue. PRX is stable under ambient temperature and air atmosphere, and it can be preserved for long-term storage under ambient temperature and in air atmosphere.
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The Thermal Decomposition mechanism of irbesartan
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Abstract Irbesartan (IBS) is an inhibitor of angiotensin II receptor. In order to study the Thermal stability and the Thermal Decomposition mechanism of IBS, the Thermal Decomposition processes of IBS in nitrogen and in air atmospheres were studied by means of thermogravimetry (TG) and differential scanning calorimetry (DSC), the evolved gaseous products from Thermal Decomposition were identified with thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR), and the residues of Thermal Decomposition at various temperatures were analyzed with infrared spectra, high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC–MS). The molecular bond orders were calculated by GAMESS program of quantum chemistry, and the Thermal Decomposition mechanism of IBS was discussed. The results indicated that the Thermal Decomposition of IBS is a three-stage process and the initial temperatures of the Decomposition are 204.7 and 201.0 °C in nitrogen and in air, respectively. The initial step of the Decomposition is the partial Decomposition of imidazolone and tetrazol sections. The Thermal stability of IBS is quite good in the routine temperature.
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Thermal Decomposition mechanism and kinetics of gemcitabine
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Abstract Gemcitabine (GTB) is a nucleoside drug used in chemotherapy for various carcinomas. In order to know why does GTB have good Thermal stability, and to further understand the relationship between Thermal stability and molecular structure. The Thermal Decomposition of GTB was measured with various Thermal analytical techniques, the gaseous products and the residues of Thermal Decomposition were determined and identified. The molecular bond orders were calculated. The Thermal Decomposition mechanism of GTB was discussed. The Thermal Decomposition kinetics and the prospective lifetime of GTB were studied using the ATSM method. The results indicated that two strong electronegative fluorine atoms on furan ring make the strong charge-transfer (CT) structure to be formed, this strong CT structure remarkably enhance the N-glycosidic bond and the weakest bond, and lead to higher Thermal stability and distinctive Thermal Decomposition mechanism. The Thermal Decomposition of GTB is a three-stage process. The initial step of Decomposition is likely due to the loss of a furan ring. Most of GTB decompose and carbonizes directly to form insoluble substance and small molecules and just part of GTB decompose by way of cytosine stage. The initial Decomposition temperature in either nitrogen or air is 235 °C. For Decomposition in nitrogen, the apparent activation energy Ea and pre-exponential factor A for the initial Thermal Decomposition are 123.4 kJ mol−1 and 3.80 × 1010 min−1, respectively. For Decomposition in air, the corresponding Ea and A are 126.3 kJ mol−1 and 7.94 × 1010 min−1, respectively. GTB has very good Thermal stability under routine temperature and dry air atmosphere.
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The Thermal Decomposition mechanism and kinetics of tenoxicam
Journal of Analytical and Applied Pyrolysis, 2018Co-Authors: Jin-Zong You, Xue-jie WangAbstract:Abstract Tenoxicam (TNX) is a non-steroidal anti-inflammatory drug. Its Thermal Decomposition processes were studied with thermogravimetry and differential Thermal analysis. The produced gaseous products and residues during Decomposition were detected and characterized using Fourier transform infrared spectroscopy. Combining with the molecular bond order distribution obtained from the quantum chemistry calculation, the Thermal Decomposition mechanism of TNX has been speculated. The kinetic parameters for Thermal Decomposition, such as activation energy Eα and the pre-exponential factor A, were obtained using the ATSM E1641 method. The prospective lifetime of TNX was estimated using the ATSM E1877 method. The results indicated that the Thermal Decomposition of TNX is a three-stage process. During the first stage of Thermal Decomposition, the main part of the molecule, including sulfamide, thiophene and amide, decompose simultaneously, and to form gasifiable small molecules and carbonized residues. The initial Decomposition temperature in either nitrogen or air is about 204°C. For Decomposition in nitrogen, the Eα and A for the initial Thermal Decomposition are 174.8 kJ mol−1 and 2.512 × 1017 min−1, respectively. For Decomposition in air, the corresponding Eα and A are 179.4 kJ mol−1 and 7.943 × 1017 min−1, respectively. The TNX has good Thermal stability under routine temperature.
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Study on the Thermal Decomposition of famciclovir
Journal of Thermal Analysis and Calorimetry, 2017Co-Authors: Jin-Zong You, Xue-jie WangAbstract:The Thermal Decomposition of famciclovir (FCV) was measured with thermogravimetry, differential scanning calorimetry, and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The IR spectra, high-performance liquid chromatography, and liquid chromatography–mass spectrometry of FCV and the residues of its Thermal Decomposition at various temperatures were determined. The molecular bond orders were calculated using an ab initio method from the GAMESS program of quantum chemistry. The mechanism of Thermal Decomposition for FCV was discussed. The kinetic parameters for Thermal Decomposition such as activation energy E a and the pre-exponential factor A were obtained using the Ozawa method. The prospective lifetime of FCV was estimated using the Dakin equation. The results indicated that the Thermal Decomposition of FCV is a two-step process. The initial Decomposition temperature in either nitrogen or air is about 205 °C. The Decomposition of FCV does not go through 2-amino-purine stage, 2-amino-purine, and alkane chain segment both decompose simultaneously during the first stage. For Decomposition in nitrogen, the E a and A for the initial Thermal Decomposition are 107.8 kJ mol−1 and 2.19 × 109 min−1, respectively. For Decomposition in air, the corresponding E a and A are 96.4 kJ mol−1 and 1.45 × 108 min−1, respectively. The FCV has good Thermal stability under routine temperature.
K. Muraleedharan - One of the best experts on this subject based on the ideXlab platform.
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Thermal Decomposition kinetics of potassium iodate
Journal of Thermal Analysis and Calorimetry, 2013Co-Authors: K. MuraleedharanAbstract:The effect of gamma ray irradiation on the rate and kinetics of Thermal Decomposition of potassium iodate (KIO_3) has been studied by thermogravimetry (TG) under non-isoThermal conditions at different heating rates (3, 5, 7, and 10 K min^−1). The Thermal Decomposition data were analyzed using isoconversional methods of Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and Friedman. Irradiation with gamma rays increases the rate of the Decomposition and is dependent on the irradiation dose. The activation energy decreases on irradiation. The enhancement of the rate of the Thermal Decomposition of KIO_3 upon irradiation is due to the combined effect of the production of displacements and extended lattice defects and chemical damage in KIO_3. Non-isoThermal model fitting method of analysis showed that the Thermal Decomposition of irradiated KIO_3 is best described by the contracting sphere model equation, with an activation energy value of ~340 kJ mol^−1.
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Thermal Decomposition of potassium titanium oxalate
Journal of the Serbian Chemical Society, 2011Co-Authors: K. Muraleedharan, Labeeb PashaAbstract:The Thermal Decomposition of potassium titanium oxalate (PTO) was studied using non-isoThermal thermogravimetry at different heating rates under a nitrogen atmosphere. The Thermal Decomposition of PTO proceeds mainly through five stages forming potassium titanate. The theoretical and experimen- tal mass loss data are in good agreement for all stages of the Thermal decom- position of PTO. The third Thermal Decomposition stage of PTO, the combined elimination of carbon monoxide and carbon dioxide, were subjected to kinetic analyses both by the method of model fitting and by the model free approach, which is based on the isoconversional principle. The model free analyses showed that the combined elimination of carbon monoxide and carbon dioxide and formation of final titanate in the Thermal Decomposition of PTO proceeds through a single step with an activation energy value of about 315 kJ mol -1 .
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Thermal Decomposition kinetics of potassium iodate
Journal of Thermal Analysis and Calorimetry, 2010Co-Authors: K. MuraleedharanAbstract:The rate and kinetics of the Thermal Decomposition of potassium iodate (KIO3) has been studied as a function of particle size, in the range 63–150 μm, by isoThermal thermogravimetry at different temperatures, 790, 795, 800 and 805 K in nitrogen atmosphere. The theoretical and experimental mass loss data are in good agreement for the Thermal Decomposition of all samples of KIO3 at all temperatures studied. The isoThermal Decomposition of all samples of KIO3 was subjected to both model-fitting and model-free (isoconversional) kinetic methods of analysis. It has been observed that the activation energy values are independent of the particle size. IsoThermal model-fitting analysis shows that the Thermal Decomposition kinetics of all the samples of KIO3 studied can be best described by the contracting cube equation.
V V Boldyrev - One of the best experts on this subject based on the ideXlab platform.
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Thermal Decomposition of ammonium perchlorate
Thermochimica Acta, 2006Co-Authors: V V BoldyrevAbstract:This review represents an attempt to summarize literature data on Thermal Decomposition of ammonium perchlorate. The mechanism of Thermal Decomposition and various factors which influence on the Thermal Decomposition of ammonium perchlorate are discussed.
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Thermal Decomposition of silver oxalate
Thermochimica Acta, 2002Co-Authors: V V BoldyrevAbstract:This is a review of the studies of the Thermal Decomposition of silver oxalate from 1950s through the 1990s. The role of various factors, which have influence on the Thermal Decomposition rate, is discussed. A detailed mechanism of the reaction is proposed, unsolved problems are summarised.
Z. Sun - One of the best experts on this subject based on the ideXlab platform.
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Research of Thermal Decomposition of hydrated methanesulfonates
Journal of Thermal Analysis and Calorimetry, 2004Co-Authors: J. Tian, Heng Jiang, Hong Gong, Z. SunAbstract:Hydrated methanesulfonates Ln(CH3SO3)3·nH2O (Ln=La, Ce, Pr, Nd and Yb) and Zn(CH3SO3)2·nH2O were synthesized. The effect of atmosphere on Thermal Decomposition products of these methanesulfonates was investigated. Thermal Decomposition products in air atmosphere of these compounds were characterized by infrared spectrometry, the content of metallic ion in Thermal Decomposition products were determined by complexometric titration. The results show that the Thermal Decomposition atmosphere has evident effect on Decomposition products of hydrated La(III), Pr(III) and Nd(III) methanesulfonates, and no effect on that of hydrated Ce(III), Yb(III) and Zn(II) methanesulfonates.