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Showing papers in "Journal of Thermal Analysis and Calorimetry in 1970"


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: Differential thermal analysis (DTA) of 25 oxalates in an atmosphere of oxygen and nitrogen is reported in this paper, showing that in some cases in nitrogen the metal is formed, in other cases the oxide of lowest valency state is produced, while a third group give the same oxide product in nitrogen and oxygen.
Abstract: Differential thermal analysis (DTA) of some 25 oxalates are reported in atmospheres of oxygen and nitrogen. It is shown that in some cases in nitrogen the metal is formed, in other cases the oxide of lowest valency state is produced, while a third group give the same oxide product in nitrogen and oxygen. The production in oxygen of the oxide for the first group, and of a higher oxide in the second group is a phenomenon which in the first case involves a further reaction of the metal with the oxygen atmosphere. Another group of oxalates produce characteristic DTA curves due to the formation of carbonate as the initial decomposition product. The dehydrations of these oxalates are marked by endothermic peaks.

125 citations


Journal ArticleDOI
TL;DR: In this paper, a general method of thermal analysis is presented, whose aim is to reduce at will pressure and temperature gradients inside the sample submitted to thermolysis, by controlling the sample temperature so as to keep constant a parameter related to the decomposition rate.
Abstract: A general method of thermal analysis is presented, whose aim is to reduce at will pressure and temperature gradients inside the sample submitted to thermolysis. The basic idea is to control the sample temperature so as to keep constant a parameter related to the decomposition rate. Attention is specially called on the case when the controlled parameter is pressure, which allows to monitor at the same time two parameters (pressure and decomposition rate). As an example, one apparatus is described, working in the pressure range between 20 and 10−3 torr. This method of Constant Rate Thermal Analysis (CRTA) appears to be specially suited for thermal analysis under controlled vacuum, for the preparation of well defined porous samples, and for the study of decomposition mechanisms.

113 citations


Journal ArticleDOI
TL;DR: The theory of Borchardt and Daniels for the determination from the DTA curve of the fraction decomposed (α) is used in this article, where the probable mechanism, activation energy (E) and frequency factor (Z) can be found by the trial and error method from the plot of α vs.T for a decomposition reaction which can be expressed by the equation..............============
Abstract: The theory of Borchardt and Daniels for the determination from the DTA curve of the fraction decomposed (α) is used. The probable mechanism, activation energy (E) and frequency factor (Z) can be found by the trial and error method from the plot ofα vs.T for a decomposition reaction which can be expressed by the equation $$\log g(\alpha ) = \log p(E/RT) + \frac{{ZE}}{{Rq}}$$

63 citations


Journal ArticleDOI
TL;DR: In this article, the stoichiometry of various stages involved in the thermal decomposition of ammonium metavanadate has been shown to correspond to a stepwise decrease in the ratio of ammonia and water to V2O5, with V 2O5 being the final product in vacuum, in air and in argon.
Abstract: The stoichiometry of the various stages involved in the thermal decomposition of ammonium metavanadate has been shown to correspond to a stepwise decrease in the ratio of ammonia and water to V2O5, with V2O5 being the final product in vacuum, in air and in argon. In ammonia, VO2 is formed. The actual stages and intermediates are dependent upon the prevailing atmosphere. Chemical analyses, together with infrared absorption spectra and X-ray powder data, have enabled the intermediates and products to be characterized and the structural changes involved in the decomposition to be discussed.

34 citations


Journal ArticleDOI
TL;DR: A microcombustion procedure for the determination of total-, organic-and carbonate-C in freshwater lake sediments is described in this paper, which involves combustion of the sample at 650° to obtain organic-C Total-C is obtained by combustion at 950° and carbonateC calculated by difference The procedure was evaluated by differential thermal analyses of representative sediments and known carbonate minerals.
Abstract: A microcombustion procedure specific for the determination of total-, organic- and carbonate-C in freshwater lake sediments is described The procedure involves combustion of the sample at 650° to obtain organic-C Total-C is obtained by combustion at 950° and carbonate-C calculated by difference The procedure was evaluated by differential thermal analyses of representative sediments and known carbonate minerals A procedure for the identification of dolomite in lake sediments by differential thermal analysis under CO2 is also described

31 citations


Journal ArticleDOI
TL;DR: In this paper, a hyperbolic heating program was proposed to integrate the general kinetic equation, which enables the integration of the generalized kinetic equation into a general heating program and enables the general equation to be integrated.
Abstract: A hyperbolic heating program enables us to integrate the general kinetic equation.

28 citations


Journal ArticleDOI
TL;DR: In this article, the symmetry of the coordina tion sphere of the central atom has been established in the intermediate products formed by the thermal decomposition of cobalt(II) complexes.
Abstract: On the basis of the thermal investigation of MpynX z mixed complexes (where M=Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+; py=pyridine; orα-, Β- andγ-picoline; X=Cl−, Br−, I−, OCN−, SCN−, NO 3 − , SO 4 2− ; andn=2,3,4,6;z=1,2), factors influencing the stability of the metal-pyridine-N bond have been determined. On the basis of the measured magnetic susceptibilities the symmetry of the coordina tion sphere of the central atom has been established in the intermediate products formed by the thermal decomposition of cobalt(II) complexes.

26 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the thermal properties of dehydrodivanillin and dehydrodiisoeugenol as model biphenyl and phenylcoumarane structural units in the lignin molecule.
Abstract: Compounds acting as model biphenyl and phenylcoumarane structural units in the lignin molecule (dehydrodivanillin and dehydrodiisoeugenol) were investigated by thermal analysis. The results were compared with previously obtained data on the thermal degradation of model phenylpropane monomer units of lignin. It was found that the mechanism of thermal degradation of these models and the thermal stabilities of the bonds depend on the structure. The thermal stability of the models increases in the absence of reactive functional groups in the side chain.

19 citations


Journal ArticleDOI
TL;DR: In this paper, an iterative procedure is suggested, which eliminates the inaccuracy of Doyle's method and permits the derivation of activation energies with an accuracy of ± 0.1 kcal/mole in ideal cases.
Abstract: Doyle's isothermal method is analysed by using it for deriving activation energies from theoretical curves. Empirical formulae are given for the time correctiontc, as well as for the factorr in the following equation:Ea=−rm cal/mole. An iterative procedure is suggested, which eliminates the inaccuracy of Doyle's method and permits the derivation of activation energies with an accuracy of ±0.1 kcal/mole in ideal cases.RésuméOn analyse la méthode isotherme de Doyle en l'employant pour le calcul des énergies d'activation sur des courbes théoriques. On donne des formules empiriques pour la correction du tempstc, ainsi que pour le facteurr dans l'équationEa=−rm cal/mole. On propose un procédé itératif éliminant l'incertitude de la méthode de Doyle et permettant le calcul des énergies d'activation à±0.1 kcal/mole dans les cas idéals.ZusammenfassungDie Doylesche isothermische Methode wurde analysiert, indem man sie zur Ableitung der Aktivierungsenergiewerte aus theoretischen Kurven heranzog. Empirische Formeln für die Zeitkorrekturtc und für den Faktorr in der GleichungEa=−rm cal/Mol wurden gegeben. Eine Iterationsmethode durch welche die Ungenauigkeit der Doyleschen Methode beseitigt und die Werte der Aktivierungsenergien auf ±0.1 Kcal/Mol Genauigkeit für den Idealfall bestimmt werden können, wurde vorgeschlagen.РезюмеПроанализирован изо термический метод До йля при его использовани и для расчета энергии акти вации по теоретическ ой кривой. Приведены эмпиричес кие формулы для коррекции времен иtc и для фактораr в сле дующем уравнении: Ea=−rm кал/мол. Предлагается прибли женный метод, исключа ющий неточность метода До йля и дающий возможность расчита ть энергию активации с точностью ±0,1 ккал/мол в идеальном случае.

18 citations


Journal ArticleDOI
TL;DR: In this paper, the shape, size, and ratio of the segments of the curves obtained during the heating were determined for quantitative analysis of mixtures of copper and/or copper oxides.
Abstract: The thermogravimetry of mixtures of metallic copper and copper oxides was studied. The experiments were performed by heating the samples in air to 700–800° to transform all the components to copper(II) oxide, and continuing the heating in nitrogen to 1050–1100° when the dissociation of copper(II) oxide to copper(I) oxide is complete. The identification of the components and their quantitative determination were carried out by determining the shape, size, and ratio of the segments of the curves obtained during the heating. The method can be used for quantitative analysis of mixtures of copper and/or copper oxides.

Journal ArticleDOI
TL;DR: In this paper, the problems on adjustment of the equipment and on data evaluation, in view of the equations derived earlier for the calculation of specific heat and heat of transformation are discussed, and quantitative determinations are possible also if the adjustment is "non-ideal" and that both air and an inert material, respectively, may be used as reference material.
Abstract: Some problems on adjustment of the equipment and on data evaluation, in view of the equations derived earlier for the calculation of specific heat and heat of transformation are discussed. It is shown that quantitative determinations are possible also if the adjustment is “non-ideal” and that both air and an inert material, respectively, may be used as reference material.

Journal ArticleDOI
TL;DR: In this paper, the activation energy, frequency factor and reaction order of malonic acid were determined from thermal decomposition curves employing different calculation methods, including the DTG curve, using a derivatograph.
Abstract: The thermal decomposition of malonic acid was investigated with a derivatograph. Values of activation energy, frequency factor and reaction order were determined from thermal decomposition curves employing different calculation methods. Equations derived for the calculation of kinetic data of inorganic thermal reactions were also found to be suitable in the case of organic reactions. Convenient methods were developed for the calculation of the activation energy, using the DTG curve.

Journal ArticleDOI
TL;DR: In this article, the thermal stability and non-isothermal kinetics of the decomposition of alkali metal bifluorides were studied using a derivatograph, and it was found that thermal stability increases with increasing ionic radius of the cation, reflecting its correlation with the hydrogen bond strength.
Abstract: The thermal stability and non-isothermal kinetics of the decomposition of alkali metal bifluorides were studied using a derivatograph. The removal of hydrogen fluoride from LiF · HF and NaF · HF takes place before melting and their decomposition occurs in a single stage; however, potassium, rubidium and cesium bifluorides at first undergo polymorphous transformation and melting on heating, and their decomposition proceeds stepwise. The thermal stability of alkali metal bifluorides has been found to increase with increasing ionic radius of the cation, reflecting its correlation with the hydrogen bond strength in these compounds.

Journal ArticleDOI
TL;DR: In this article, a new method is proposed for the derivation of kinetic parameters of reactions in homogeneous systems, by carrying out kinetic measurements under conditions of programmed temperature variations, instead of performing them under isothermal conditions at different temperatures.
Abstract: A new method is proposed for the derivation of kinetic parameters of reactions in homogeneous systems, by carrying out kinetic measurements under conditions of programmed temperature variations, instead of performing them under isothermal conditions at different temperatures. The basic relations are given for simple, paralle and complex reactions, without specifying the analytical shape of the temperature programme function.

Journal ArticleDOI
TL;DR: In this article, it was inferred from the thermoanalytical data obtained on 0.2-4.0M solutions of Fe(ClO4)2 which are frozen under non-equilibrium conditions that the phase containing the solute ions turns into a glassy state below −95°.
Abstract: It is inferred from the thermoanalytical data obtained on 0.2–4.0M solutions of Fe(ClO4)2 which are frozen under non-equilibrium conditions that the phase containing the solute ions turns into a glassy state below −95°. On the warming of these solutions exothermic and endothermic processes are observed which can be related to the effects observed by the nuclear gamma resonance method.

Journal ArticleDOI
TL;DR: In this paper, the first-order inversion of tridymite has been shown to exhibit considerable variation, and is not a constant of trithymite, and a method for determining equilibrium transition temperatures from dynamic data is presented.
Abstract: Tridymite has been produced from a variety of fluxes. Most samples gave two first-order inversions at ∼117 and ∼163°. Calorimetric study shows that the heats of inversion exhibit considerable variation, and are thus not constants of tridymite. These differences are related to the polytypism and disorder. The 117° inversion occurs with considerable hysteresis: a method for determining equilibrium transition temperatures from dynamic data is presented. Some of the tridymite samples also exhibited a second-order inversion in the range 230–250°.

Journal ArticleDOI
TL;DR: The spiral vacuum microbalance for studies of the kinetics of mass changes of solids at high temperatures is described in this article, where some novel improvements ensure high sensitivity of the balance and stability of temperature and pressure.
Abstract: The spiral vacuum microbalance for studies of the kinetics of mass changes of solids at high temperatures is described. Some novel improvements ensure high sensitivity of the balance and stability of temperature and pressure. Results of studies on the kinetics of the oxidation of copper carried out at 1000‡ prove the suitability of this balance in the investigation of kinetics of heterogenous reactions.

Journal ArticleDOI
TL;DR: In this paper, the authors untersucht, unter welchen Bedingungen das Proton einer ionischen OH−-Gruppe die Elektronenwolke des O2−Ions verlassen kann, um with einer benachbarten OH−−-gruppe ein H2O-Molekul zu bilden.
Abstract: Man untersucht, unter welchen Bedingungen das Proton einer ionischen OH−-Gruppe die Elektronenwolke des O2−Ions verlassen kann, um mit einer benachbarten OH−-Gruppe ein H2O-Molekul zu bilden. Voraussetzung zum Tunneln ist in der benachbarten OH−-Gruppe ein freies Akzeptorniveau auf gleicher Hohe. Wenn die beiden betrachteten OH−-Gruppen kristallographisch aquivalent sind, ist die letztgenannte Bedingung nicht erfullt, da das Akzeptorniveau hoher liegt als das Donatorniveau. Durch Koplung mit den gegenphasigen OH-Knickschwingungen wird eine Verbreiterung der Niveaus und schlieslich — ab einer “kritischen” Amplitude — eine Uberlappung herbeigefuhrt, die das Tunneln ermoglicht. Die Protonenumlagerung beginnt an der Oberflache, weil an einer freien Oberflache die Amplituden der wirksamen OH-Knickschwingungen bei gleicher Temperatur groser sind als im Innern des Kristalls.

Journal ArticleDOI
TL;DR: In this article, the authors studied the thermal decomposition of diammonium hydrogenphosphate (NH4)2HPO 4 using a fluidized bed and showed that for the same size of particle at the same temperature, but for different carrier gases, the rate constant and activation energy increase in the following order: air, methane, hydrogen.
Abstract: Reliable thermodynamic parameters for the thermal decomposition of diammonium hydrogenphosphate [(NH4)2HPO 4] may be obtained using a fluidized bed. For the same size of particle, at the same temperature, but for different carrier gases, the rate constant and activation energy increase in the following order: air, methane, hydrogen. Por the same carrier gas (air) the rate constant increases when the particle size decreases. It is well known that diammonium hydrogenphosphate is a constituent of fertilizers. The thermal decomposition of pure diammonium hydrogenphosphate and of fertilizers containing this salt has been studied [1 - 6] but no kinetic study of the decomposition has been made so far. One of the major problems associated with the kinetics of solid state reactions is the evaluation of activation energies and related parameters for clearly identified processes beginning from the initial portion of nucleation, through the various intermediate phases to the final stages of decomposition [7]. In order to study the thermal decomposition of (NH~)2HPO4, the isothermal method in a fluidized bed has been utilized. This method has been elaborated by Kr6bl [8] in order to study the thermal decomposition of cobalt (llI)-amino complexes. An outline of the apparatus is shown in Fig. 1. Air, methane and hydrogen were used in order to study the influence of carrier gas upon kinetic parameters. The pressure of the gases was constant and equal in every case. The flow rate was 8 l/h. Ammonia evolved during the decomposition of (NH~)2HPO 4 was trapped in a 0.01 N H2SO4 solution. A 1 : t mixture of methyl red with methylene blue was used as indicator. In order to study the influence of particle size upon kinetic parameters, we always worked with 0.0611 g (NHa)2HPO 4 of the following sizes: 0.10-0.07 mm; 0.20-0.15 ram; 0.30-0.25 mm and 0.40-0.43 mm. That such small quantities are required is a fact of considerable importance in the study of the thermal decomposition. An equation was sought which well describes the kinetics of thermal decomposition. Taking into account the complexity of the process, there is little chance of finding a general equation capable of describing the kinetics of all thermal decomposition reactions, especially in the case when the kinetics vary during the process [9].

Journal ArticleDOI
TL;DR: In this paper, two batches of wustite were produced from a stoichiometric mixture of Fe and Fe2O3 by sealing in steel tubes in vacuum and helium, respectively, and igniting the first tube at 1300° for 21 hours and the second one at 1200° for 34 hours.
Abstract: Two batches of wustite were produced from a stoichiometric mixture of Fe and Fe2O3 by sealing in steel tubes in vacuum and helium, respectively, and igniting the first tube at 1300° for 21 hours and the second one at 1200° for 34 hours. There were two exothermic peaks on the DTA curves of both samples at 345 and 545 to 700° due to surface oxidation of FeO to Fe3O4 followed by bulk oxidation of FeO to Fe3O4 and of Fe3O4 toα-Fe2O3. The last two reactions gave rise to a dual (or twin) peak for coarse material but one peak in the case of fine material, indicating that the two reactions occurred concurrently for fine material. Similar investigations on both fine and coarse magnetites showed only two exothermic peaks which corresponded to surface and bulk oxidation, respectively. This result confirms the previous observations that coarse magnetite converts toα-Fe2O3 by surface oxidation followed by bulk oxidation.

Journal ArticleDOI
TL;DR: In this article, a systematic study of this phenomenon using pure compounds with controlled grain size and other affecting parameters may help in understanding the dissociation curves of natural carbonate aggregates.
Abstract: Differential thermal investigations with pure synthetic carbonate minerals revealed a general lowering of the dissociation peak for magnesite, dolomite or calcite when present together in an artificial mixture. The presence of siderite did not affect the dissociation curves of these carbonates. A systematic study of this phenomenon using pure compounds with controlled grain size and other affecting parameters may help in understanding the dissociation curves of natural carbonate aggregates.

Journal ArticleDOI
TL;DR: In this paper, the properties of the thiocarbonates of K, Tl, Pb, Cd, Cc, Co, Ni, Zn, Fe, Sb, and Sb(III) have been studied by thermogravimetric analysis.
Abstract: The thiocarbonates of K(I), Tl(I), Pb(II), Cd(II), Cu(II), Co(II), Ni(II), Zn(II), Fe(II) and the sulphides of Ag(I), Cu(II), Cd(II), Hg(II), Bi(III), Mo(VI), Pt(IV), Au(III), V(V), Se(IV), Te(IV), As(III, V), Sb(III) have been studied by thermogravimetric analysis. These studies not only confirm the purity of the precipitated products obtained with PTC but also determine correct temperature ranges for the precipitates to attain constant weight, thereby affording gravimetric evaluations of even mg quantities of the metal ions studied. Purity of precipitated products was made possible with the technique of precipitation from homogeneous solution based on the PTC reagent as precipitant.

Journal ArticleDOI
TL;DR: The stoichiometry of the thermal decomposition reaction of Na3[Co(NO2)6] was studied by TG, DTA and mass spectrometric analysis as mentioned in this paper.
Abstract: The stoichiometry of the thermal decomposition reaction of Na3[Co(NO2)6] was studied by TG, DTA and mass spectrometric analysis.

Journal ArticleDOI
TL;DR: In this article, an attempt is made to relate thermal stability order to relative heats of formation and stereochemistry, but no relationship exists between thermal stability orders of the chelates and hydrolytic stability orders, infrared band shifts or force constants.
Abstract: Thermogravimetric studies of divalent metal chelates of eight common amino acids have revealed that no relationship exists between thermal stability orders of the chelates and hydrolytic stability orders, infrared band shifts or force constants. An attempt is made to relate thermal stability order to relative heats of formation and stereochemistry.

Journal ArticleDOI
TL;DR: New types of crucibles for thermogravimetry and differential thermal analysis are described for use with conventional equipment, enabling extremely rapid movement of the gaseous species through the sample and sample holder as mentioned in this paper.
Abstract: New types of crucibles for thermogravimetry and differential thermal analysis are described for use with conventional equipment, enabling extremely rapid movement of the gaseous species through the sample and sample holder. Its use in studies of oxidation or decomposition reactions is illustrated by considering the oxidation of UO2 and the decomposition of CaC2O4·H2O.

Journal ArticleDOI
TL;DR: In this paper, a method of thermal gas evolution from a fluidized bed (FTGE) with continuous and linear increase of temperature was worked out and the thermal decomposition of diammonium hydrogen phosphate was followed.
Abstract: In order to eliminate the errors of the TG method with a static layer, and to determine the influence of the heating rate, the composition of the carrier gas and the particle size of the solids, a method of thermal gas evolution from a fluidized bed (FTGE) with continuous and linear increase of temperature was worked out and the thermal decomposition of diammonium hydrogen phosphate was followed. This method gives reproducible results and makes possible the determination of the apparent activation energies and kinetic parameters.RésuméDans le but d'éliminer les erreurs des procédés thermogravimétriques avec couches fixes, et de mettre en évidence l'influence de la vitesse d'échauffement de la composition du gaz porteur et de la dimension des solides, on a développé une méthode d'analyse des gaz dégagés, avec lit fluidifié et élévation de la température continue et linéaire. On a suivi ainsi la décomposition thermique de (NH4)2HPO4. Cette méthode donne des résultats reproductibles et rend possible la détermination des énergies d'activation apparentes et des paramètres cinétiques.ZusammenfassungUm die Fehler der TG Methode unter fixierten Verhältnissen zu eliminieren, den Einfluß der Temperaturerhöhung, der Zusammensetzung des Trägergases und des Ausmaßes der Festkörper zu klären, wurde eine thermogasanalytische Methode im fluidisierten Bett (FTGE) mit kontinuierlichem und linearem Temperaturanstieg entwickelt und die thermische Zersetzung des Diammonium-biphosphates verfolgt. Man erhielt mit dieser Methode reproduzierbare Ergebnisse. Sie ist zur Bestimmung der scheinbaren Aktivierungsenergien und kinetischer Parameter geeignet.РезюмеДля исключения ошибо к метода ТГ в неподвиж ном слое, выяснения влиян ия скорости нагрева и со става газа носителя, а также навески твердого обр азца разработан новый метод в кипящем слое с постоянным и ли нейным повышением температ уры. Этим методом изучен термо распад двухзамещенн ого фосфата аммиака. Метод дает во спроизводимые результаты, что делае т возможным определе ние кажущейся энергии ак тивации и кинетических парам етров.

Journal ArticleDOI
TL;DR: In this paper, the problems of vaporization and sublimation have been avoided through the use of sealed glass vials, which are still more than adequate for chemical analysis by instrumental methods such as infrared spectroscopy and gas chromatography.
Abstract: Many chemical systems illustrating major reaction types may be conveniently studied by differential thermal analysis. The problems of vaporization and sublimation have been avoided through the use of sealed glass vials. Sample sizes are in the range of 10 to 100 milligrams. This size though small is still more than adequate for chemical analysis by instrumental methods such as infrared spectroscopy and gas chromatography.

Journal ArticleDOI
TL;DR: In this paper, a set of 12 organischen Verbindungen wurde festgestellt, das aus Paraffin-Kohlenwasserstoffen sowie aus aromatischen Kohlen-wasser stoffen, die vor Beginn der thermischen Zersetzung sublimieren.
Abstract: Auf Grund der differentialthermoanalytischen und thermogravimetrischen Untersuchurg von 12 organischen Verbindungen wurde festgestellt, das aus Paraffin-Kohlenwasserstoffen sowie aus aromatischen Kohlenwasserstoffen, die vor Beginn der thermischen Zersetzung sublimieren, ziemlich wenig Koksruckstand erhalten wird. Die Sauerstoff und Stickstoff enthaltenden heterocyclischen Verbindungen wie Brazan und Carbazol bilden durch Polymerisations- und Kondensationsprozesse eine feste Phase kohlenstoffreicher, nicht fluchtiger, hocharomatischer Produkte. Die hochmolekularen, schwer schmelzbaren und siedenden aromatischen Verbindungen, wie Truxen und Difluorenyl, zeigen vor der thermischen Zersetzung und Verdampfung exothermische Polymerisations- und Polykondensationsprozesse. Aus diesen Verbindungen erhalt man viel festen, nicht fluchtigen Ruckstand.

Journal ArticleDOI
G. W. Miller1, J. L. Wood1
TL;DR: In this article, the probable accuracy of the Du Pont 1200 ‡C cell has been described, with proper attention to technique, with a slightly larger deviation of about ± 5 % in accuracy.
Abstract: The probable calorimetric accuracy of the Du Pont 1200 ‡C cell has been described. With proper attention to technique, calorimetric precision of about ±2% can be obtained with a slightly larger deviation of about ±5 % in accuracy. The heat flow calibration constant,E, is linear with temperature, and its value is two to four times that of commercial scanning calorimeters.