Thermal decomposition of nicotinate complexes of cobalt and nickel in dynamic nitrogen atmosphere

1994 ◽  
Vol 41 (4) ◽  
pp. 859-870
Author(s):  
M. A. M. Al-Gurashi ◽  
A. A. B. El-Ahmadi ◽  
S. M. A. Katib ◽  
K. M. Abd El-Salaam
Keyword(s):  
Thermal Decomposition ◽  
Nitrogen Atmosphere ◽  
Cobalt And Nickel

Non-Isothermal Decomposition Kinetic of Polypropylene/Hydrotalcite Composite

2019 ◽  
Vol 19 (11) ◽  
pp. 7493-7501 ◽  
Author(s):  
Sheng Xu ◽  
Min Zhang ◽  
Siyu Li ◽  
Moyu Yi ◽  
Shigen Shen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Nitrogen Atmosphere ◽  
Heating Rates ◽  
Decomposition Reactions ◽  
Kinetic And Thermodynamic Parameters ◽  
Málek Method ◽  
Boundary Reaction ◽  
Phase Boundary Reaction ◽  
Thermal Stability Of

P3O5-10 pillared Mg/Al hydrotalcite (HTs) as a functional fire-retarding filler was successfully prepared by impregnation-reconstruction, where the HTs was used to prepare polypropylene (PP) and HTs composite (PP/HTs). Thermal decomposition was crucial for correctly identifying the thermal behavior for the PP/HTs, and studied using thermogravimetry (TG) at different heating rates. Based on single TG curves and Málek method, as well as 41 mechanism functions, the thermal decompositions of the PP/HTs composite and PP in nitrogen atmosphere were studied under non-isothermal conditions. The mechanism functions of the thermal decomposition reactions for the PP/HTs composite and PP were separately “chemical reaction F3” and “phase boundary reaction R2,” which were also in good agreement with corresponding experimental data. It was found that the addition of the HTs increased the apparent activation energy Ea of the PP/HTs comparing to the PP, which improved the thermal stability of the polypropylene. A difference in the set of kinetic and thermodynamic parameters was also observed between the PP/HTs and PP, particularly with respect to lower ΔS≠ value assigned to higher thermal stability of the PP/HTs composite.

scholarly journals Thermal decomposition characteristics of foundry sand for cast iron in nitrogen atmosphere

2018 ◽  
Vol 5 (12) ◽  
pp. 181091 ◽  
Author(s):  
Qingwei Xu ◽  
Kaili Xu ◽  
Xiwen Yao ◽  
Jishuo Li ◽  
Li Li
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Cast Iron ◽  
Low Cost ◽  
Temperature Stability ◽  
Nitrogen Atmosphere ◽  
High Temperature Stability ◽  
Kinetics Parameters ◽  
Foundry Sand ◽  
Exponential Factor

Sand casting, currently the most popular approach to the casting production, has wide adaptability and low cost. The thermal decomposition characteristics of foundry sand for cast iron were determined for the first time in this study. Thermogravimetry was monitored by simultaneous thermal analyser to find that there was no obvious oxidation or combustion reaction in the foundry sand; the thermal decomposition degree increased as the heating rate increased. There was an obvious endothermic peak at about 846 K due to the transition of quartz from β to α phase. A novel technique was established to calculate the starting temperature of volatile emission in determining the volatile release parameter of foundry sand for cast iron. Foundry sand does not readily evaporate because its volatile content is only about 2.68 wt% and its main components have high-temperature stability. The thermal decomposition kinetics parameters of foundry sand, namely activation energy and pre-exponential factor, were obtained under kinetics theory. The activation energy of foundry sand for cast iron was small, mainly due to the wide temperature range of thermal decomposition in the foundry sand.

Synthesis and Thermal Characterization of Luminescent Powers of Terbium (III) with Mixed Ligands

2005 ◽  
Vol 498-499 ◽  
pp. 535-539
Author(s):  
Crislene Rodrigues da Silva Morais ◽  
Wilton Silva Lopes ◽  
A.G. de Souza ◽  
P.D. Santa-Cruz
Keyword(s):  
Thermal Decomposition ◽  
Elemental Analysis ◽  
Metal Ion ◽  
Gas Flow ◽  
Thermal Characterization ◽  
Nitrogen Atmosphere ◽  
Experimental Conditions ◽  
Mixed Ligands ◽  
Differential Calorimeter ◽  
Dsc Curves

This work deals with the synthesis and thermal decomposition of complexes of general formula: Ln(ß-dik)3L (where Ln=Tb+3, ß-dik=4,4,4-trifluoro-1-phenyl-1,3- butanedione(btfa) and L=1,10-fenantroline(phen) or 2,2-bipiridine(bipy). The powders were characterized by melting point, FTIR spectroscopy, UV-visible, elemental analysis, scanning differential calorimeter(DSC) and thermogravimetry(TG). The TG/DSC curves were obtained simultaneously in a system DSC-TGA, under nitrogen atmosphere. The experimental conditions were: 0.83 ml.s-1 carrier gas flow, 2.0±0.5 mg samples and 10°C.min-1 heating rate. The CHN elemental analysis of the Tb(btfa)3bipy and Tb(btfa)3phen complexes, are in good agreement with the expected values. The IR spectra evinced that the metal ion is coordinated to the ligands via C=O and C-N groups. The TG/DTG/DSC curves of the complexes show that they decompose before melting. The profiles of the thermal decomposition of the Tb(btfa)3phen and Tb(btfa)3bipy showed six and five decomposition stages, respectively. Our data suggests that the thermal stability of the complexes under investigation followed the order: Tb(btfa)3phen < Tb(btfa)3bipy.

Thermal decomposition of basic zinc carbonate in nitrogen atmosphere

2004 ◽  
Vol 414 (2) ◽  
pp. 121-123 ◽  
Author(s):  
Yanhua Liu ◽  
Jingzhe Zhao ◽  
Hui Zhang ◽  
Yanchao Zhu ◽  
Zichen Wang
Keyword(s):  
Thermal Decomposition ◽  
Nitrogen Atmosphere ◽  
Zinc Carbonate

scholarly journals Thermal decomposition kinetics of raw and treated olive waste

2019 ◽  
Vol 23 (6 Part A) ◽  
pp. 3501-3512
Author(s):  
Zhihong Wang ◽  
Chengzhang Wang ◽  
Mijun Peng
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermodynamic Characteristics ◽  
Nitrogen Atmosphere ◽  
Enzyme Hydrolysis ◽  
Conversion Degree ◽  
Thermal Decomposition Mechanism ◽  
Scanning Calorimetry ◽  
Two Samples ◽  
Olive Waste

The pyrolysis characteristic of raw and ultrasound assisted enzyme hydrolysis treated (UAEH) olive waste was investigated using the thermogravimetric analysis at 5, 10, 15, and 20?C per minute in the nitrogen atmosphere. The thermal decomposition was divided into three stages in the thermograph curve, and the thermogravimetric curve showed the same decomposition trend for two samples. The temperature interval and peak temperature were different for two different samples, and moved to higher temperature with the increase in heating rate. Differential thermogravimetric and differential scanning calorimetry curves depicted that the structure and composition of samples were changed by UAEH. Meanwhile, the kinetic parameters were calculated by the Kissinger, Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa, and Coats-Redfern methods. For untreated and treated olive waste, the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa methods revealed the similar kinetic characteristics for the conversion degree from 0.1 to 0.9, and the average values of activation energy were 201.42 kJ/mol and 162.97 kJ/mol, respectively. The change in activation energy was clearly dependent on the extent of conversion. The Coats-Redfern method suggested the second-order model (F2, f(?) = (1 ? ?)2) could be used to better describe the thermal decomposition mechanism of untreated and treated olive waste. Besides, thermodynamic characteristics of olive waste treated were consistent with that of the untreated sample.

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