Authors:B. Zhou, S. Jiang, L. Zou, X. Wang, D. Wang, J. Liu, S. Shang, and D. Zhou
A new compound cyclohexyl-t-butyldimethylammonium tetraphenylborate, [C6H11N(CH3)2(C(CH3)3)]BPh4 has been prepared, and its decomposition mechanism was studied by TG. The IR spectra of the products of thermal decomposition were examined at every stage. Kinetic analysis for the first stage of thermal decomposition process was obtained by TG and DTG curves, and kinetic parameters were obtained from the analysis of the TG-DTG curves with integral and differential equations. The most probable kinetic function was suggested by comparison of kinetic parameters.
Authors:M. Badea, R. Olar, E. Cristurean, D. Marinescu, M. Brezeanu, M. Balasoiu, and E. Segal
This paper reports an investigation of the thermal stabilities of the class of coordination compounds containing lanthanide ions Ln(III) (Ln=La, Sm, Eu, Dy, Er), Co(II) ions and oxalate anions C2O
. The thermal decomposition steps were identified, and in some cases the values of the non-isothermal kinetic parameters were determined.
Authors:J. Zhang, L. Ge, X. Zhang, Y. Dai, H. Chen, and L. Mo
The thermal decomposition of Zn[NFA]2
5H2O (NFA=C16H18FN3O3, norfloxacin) and its kinetics were studied under non-isothermal conditions in air by TG-DTG and DTA methods. The intermediate and residue for each decomposition were identified from the TG curve. The non-isothermal kinetic data were analyzed by means of the Achar method and the Madhusudanan-Krishnan-Ninan (MKN) method. The possible reaction mechanisms were investigated by comparing the kinetic parameters. The kinetic equation for the second stage can be expressed as d/dt=Aexp(–E/RT)(1–).
Authors:Zhou Bao-xue, Zhong Wei-ke, Zou Li-zhuang, and Wang Xiao-ling
Barium(II) tetraphenylborate, Ba(Bph4))2·4H2O was prepared, and its decomposition mechanism was studied by means of TG and DTA. The products of thermal decomposition were examined by means of gas chromatography and chemical methods. A kinetic analysis of the first stage of thermal decomposition was made on the basis of TG and DTG curves and kinetic parameters were obtained from an analysis of the TG and DTG curves using integral and differential methods. The most probable kinetic function was suggested by comparison of kinetic parameters. A mathematical expression was derived for the kinetic compensation effect.
Authors:J. Zsakó, I. Ganescu, Cs. Várhelyi, and L. Chirigiu
Thermal decomposition of 6 complexes of the type AH[Cr(NCS)4 (am)2]· nH2O is studied with derivatograph. The formation of Cr(NCS)3 as a labile intermediate is presumed. For some decomposition stages kinetic parameters are derived. The kinetic compensation effect is discussed.
Authors:Daqing Wang, Baoxue Zhou, Yuanjang Jia, Feng Shi, and Yiping Fan
The complex Mn(Nica)2Cl2 (Nica=nicotinamide) was prepared, and its decomposition was studied by means of TG and DSC. The IR spectra of the products
of thermal decomposition were examined at every stage. Kinetic analysis of the first stage of thermal decomposition was performed
via the TG-DTG curves, and the kinetic parameters were obtained from analysis of the TG-DTG curves with integral and differential
methods. The most probable kinetic function was suggested from a comparison of the kinetic parameters. Mathematical expressions
were derived for the kinetic compensation effect.
Results obtained on the thermooxidative degradations of LDPE (low-density polyethylene) and NBR (nitrile-butadiene rubber)
are presented. The activation energies for the thermooxidations leading to solid products were estimated. For LDPE, the activation
energies obtained from non-isothermal data are in satisfactory agreement with those obtained from isothermal data. For NBR,
the isothermal activation energy is ≉16% higher than the non-isothermal one. This difference is due to the morphological changes
undergone by NBR during its heating at the rather high temperatures at which isothermal measurements were performed.
The condensation approximation (CA) and numerical regularization procedure (RP) methods used to solve a Fredholm integral
equation of the first kind describing the adsorption equilibria on a heterogeneous solid surface under isothermal conditions
have been adopted in the present study to evaluate desorption energy distributions from temperature-programmed desorption
(TPD) spectra. From comparisons of the computational results obtained by means of these methods on the basis of simulated
TPD spectra, it follows that the CA gives stable solutions for wide desorption energy distributions and it can be used successfully
for calculations from wide and clear resolved peaks in the TPD spectra. The use of the RP is more advantageous for acquisition
of the distributions from closely related narrow peaks in the TPD spectra.
Recently, Órfão obtained two simple equations for the estimation of the relative error in the activation energy calculated
by the integral methods . In this short communication, the validity of the equations has been evaluated by comparing the
results calculated by the equations with the results calculated by the equation from theoretical derivation without introducing
Authors:Loredana Feher, B. Jurconi, Gabriela Vlase, T. Vlase, and N. Doca
The thermooxidative degradation of three models of oily soils was studied under non-isothermal conditions, at heating rates
of 5, 10, 15 and 20�C min−1. Di-octyl-sebacate, as model for synthetic oil, was adsorbed on silica, alumina and silico-alumina, considered models for
the inorganic micelle of a soil. For a kinetic analysis, the TG data were processed by three methods: Flynn-Wall-Ozawa, Friedman
and NPK (Nomen-Sempere). The results indicate the NPK as the less speculative method that allows a separation of the elementary
steps and at the same time a separation of the temperature, respective conversion dependent part of the reaction rate.