apparent activationenergy ( E a ) for dissociation of Mn(CO) 5 from solid Mn 2 (CO) 10 . Unlike traditional mass spectrometry (which involves ionization by high-energy electrons), EGA-IAMS offers a considerable advantage in that it preserves the structure
Authors:Ahu Gümrah Dumanli, Sinem Taş, and Yuda Yürüm
be illustrated by
where A is the pre-exponential Arrhenius factor, E the activationenergy, and R the gas constant.
For dynamic data obtained at a constant heating rate
this term is inserted in Eq. 2 so the above rate
Authors:Michelle G. Mothé, Leni F. M. Leite, and Cheila G. Mothé
predictions, especially due to the combination of factors such as heat transfer, mass transfer phenomena, chemical reactions, and thermal stability [ 3 , 6 , 7 ]. Knowledge of kinetic parameters as activationenergy and pre-exponential factor would help
Authors:Yuki Kitahara, Ko Okuyama, Keita Ozawa, Takuya Suga, Seiji Takahashi, and Toshihiro Fujii
to the ion source, and hence primary degradation products may be observed by this technique, compared with conventional pyrolysis–GC/MS (Py–GC/MS).
Apparent activationenergies for decomposition of acrylamide
Authors:Marcelo Kobelnik, Douglas Lopes Cassimiro, Clóvis Augusto Ribeiro, Diógenes dos Santos Dias, and Marisa Spirandeli Crespi
at temperatures corresponding to fixed values of conversion degree (α) and the activationenergy ( E a /kJ mol −1 ) data were obtained applying the isoconversional method proposed by Capela and Ribeiro [ 9 ].
Calculation of the activationenergy by isoconversional method
Thermal transformation of crystal hydrates is a solid-state process of the type [ 22 – 28 ]: A(solid) → B (solid) + C (gas). The kinetics of such reactions is described by various
Mechanism of the processes in condensed phase are very often unknown or too complicated to be characterised by a simple kinetic
model. They tend to occur in multiple steps that have different rates. To describe their kinetics, the single-step kinetics
approximation is often applied which resides in substituting a generally complex set of kinetic equations by the sole single-step
kinetics equation. The main contribution of the single-step kinetics approximation is that it enables a mathematical description
of the kinetics of solid-state reactions without a deeper insight into their mechanism. The single-step kinetics approximation
is based on the assumption that the temperature and conversion functions are separable. In the paper, some consequences originating
from ignoring the function separability are discussed.
Authors:H. Abematsu, M. Tsuchiya, Y. Iseri, and T. Kojima
The TG studies are presented for isomers of benzimidazolyl-substituted polyamides (BIPA). The TG data are compared with those
polyamides (PA) of identical backbones without substitution, in view of the mechanism of thermal degradation. The TG mass
loss curves divided to three temperature ranges reflect the decomposition reactions in the respective temperature ranges:
(1) cleavage of single bonds of nitrogen to aromatic ring, (2) random scission of single bonds, (3) condensation of the remained
rings. Liberation of benzimidazole rings occurs in the temperature range (2). The final product, char, contains benzimidazole
rings. Terephthaloyl-rich BIPA's retard liberation of benzimidazole from the decomposed polymer.
Authors:M. M. Milanova, D. S. Todorovsky, and M. G. Arnaudov
The thermochemical behaviour of solid-state complexes of lanthanum with mono-(2-ethylhexyl) phosphoric acid (H2B) (La(HB)3·1.5H2O and La2B3·3H2O) was studied. The thermal decomposition of these complexes proceeds without melting to yield La(PO3)3 and a mixture of La(PO3)3 and LaPO4, respectively. La(HB)31.5H2O decomposes via dehydration (323–383 K), condensation of the OH-groups with formation of a diphosphate structure (383–458 K) and a stepwise degradation of the hydrocarbon chains (443–565 K). The dehydration of La2B3·3H2O (333–433 K) is followed by decomposition of the hydrocarbon group. From a combination of the present results with previous data , it was concluded that the temperatures and mechanisms of the decomposition of the hydrocarbon part of the lanthanide complexes of (2-ethylhexyl) phosphoric acids depend on the nature of the lanthanide, the atmosphere, and the structure of the complexes.