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Journal ArticleDOI

A New Method of Analyzing Thermogravimetric Data

01 Nov 1965-Bulletin of the Chemical Society of Japan (The Chemical Society of Japan 公益社団法人 日本化学会)-Vol. 38, Iss: 11, pp 1881-1886
TL;DR: In this paper, a new method of obtaining the kinetic parameters from thermogravimetric curves has been proposed, which is simple and applicable to reactions which can not be analyzed by other methods.
Abstract: A new method of obtaining the kinetic parameters from thermogravimetric curves has been proposed. The method is simple and applicable to reactions which can not be analyzed by other methods. The effect of the heating rate on thermogravimetric curves has been elucidated, and the master curve of the experimental curves at different heating rates has been derived. The applications of the method to the pyrolyses of calcium oxalate and nylon 6 have been shown ; the results are in good agreement with the reported values. The applicability of the method to other types of thermal analyses has been discussed, and the method of the conversion of the data to other conditions of temperature change has been suggested. From these discussions, the definition of the thermal stability of materials has been criticized.
Citations
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Journal ArticleDOI
TL;DR: In this article, the authors have developed recommendations for reliable evaluation of kinetic parameters (the activation energy, the preexponential factor, and the reaction model) from the data obtained by means of thermal analysis methods such as TGA, differential scanning calorimetry (DSC), and differential thermal analysis (DTA).

4,112 citations

Journal ArticleDOI
01 Mar 1971-Polymer
TL;DR: In this article, non-isothermal kinetics of nucleation and its growth are derived by extending Avrami's equation and applied to DSC curves of crystallization obtained by cooling poly(ethylene terephthalate) at constant rates.

2,102 citations

Journal ArticleDOI
TL;DR: In this article, two methods of obtaining kinetic parameters from derivative thermoanalytical curves are proposed based on the general form of kinetic formulae and are applicable to general types of reactions governed by a single activation energy.
Abstract: Two methods of obtaining kinetic parameters from derivative thermoanalytical curves are proposed The methods are based on the general form of kinetic formulae and are applicable to general types of reactions governed by a single activation energy One method utilizes the linear relation between peak temperature and heating rate in order to estimate the activation energy, and only the information of the rate of conversion versus the temperature is necessary The other method needs the information of both the conversion and the rate of conversion versus the temperature, and the Arrhenius plot is made for an assumed kinetic mechanism

1,974 citations

Journal ArticleDOI
TL;DR: A broad review of the state-of-the-art biomass pyrolysis research can be found in this article, where three major components (cellulose, hemicellulose and lignin) are discussed in detail.

1,613 citations

Journal ArticleDOI
TL;DR: The thermal stability and flame retardancy of polyurethanes is reviewed in this article, where a detailed description of TGA, TGA-MS and TGAFTIR methods for studying the decomposition mechanism and kinetics is also provided.

1,329 citations

References
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Journal ArticleDOI
01 Jan 1964-Nature
TL;DR: In this article, a thermocouple is used to measure the sample temperature in a Stanton HT-D thermobalance, the bead of which is positioned in or near the sample, depending on crucible design.
Abstract: THE use of thermogravimetric data to evaluate kinetic parameters of solid-state reactions involving weight loss (or gain) has been investigated by a number of workers1–4. Freeman and Carroll2 have stated some of the advantages of this method over conventional isothermal studies. To these reasons may be added the advantage of using one single sample for investigation. However, the importance of procedural details, such as crucible geometry, heating rate, pre-history of sample, and particle size, on the parameters has yet to be fully investigated. It is also necessary to ensure accurate temperature measurement, both for precision and also to detect any departure from a linear heating rate due to endo- or exo-thermic reactions. (The effect of these may be largely eliminated by the use of small samples.) In our present work (using a Stanton HT–D thermobalance) the sample temperature is measured directly by means of a thermocouple the bead of which is positioned in or near the sample, depending on crucible design, the wires of which run down a twin-bore rise rod. The connexion between the end of the thermocouple wires on the balance arm and the terminal block is made by 0.001 in. platinum and platinum/rhodium wires5. It has been shown that these wires do not affect the performance of the balance but act merely as a subsidiary damping. From the terminal block compensated cable leads to the cold junction and a potentiometric arrangement for direct measurement of the thermocouple output.

5,770 citations

Journal ArticleDOI
C. D. Doyle1
TL;DR: The kinetic analysis of the thermogram, by use of either its exact equation or a more convenient approximation formula, is straightforward in cases of volatilization via simple kinetics as mentioned in this paper.
Abstract: Thermogravimetric data are generally more extensive than are comparable isothermal aging data, and therefore afford preliminary kinetic information in greater abundance. The kinetic analysis of the thermogram, by use of either its exact equation or a more convenient approximation formula, is straightforward in cases of volatilization via simple kinetics. Application of the analytical procedure to the thermogram for the zero-order volatilization of octamethylcyclotetrasiloxane yielded an estimate of 11.65 kcal./mole as the average heat of vaporization in the temperature range of 80 to 145°C. The apparent activation energy for the first-order pyrolytic volatilization of 200-mg. samples of pulverized polytetrafluoroethylene was estimated to be 66 to 68 kcal./mole in the temperature range of 520 to 610°C.

1,136 citations

Journal ArticleDOI
C. D. Doyle1
TL;DR: In this paper, the authors presented a method for estimating equivalent isothermal life from thermogravimetric data and for estimating the apparent activation energy for volatilization even though the nature of the kinetic process is unknown.
Abstract: Equations are given for estimating equivalent isothermal life from thermogravimetric data and for estimating the apparent activation energy for volatilization even though the nature of the kinetic process is unknown. Illustrative data for polytetrafluoroethylene are presented. The importance of using sample temperatures, rather than furnace temperatures, is noted.

907 citations