Studies on metal hydroxy compounds. XI. Thermal analyses, decomposition kinetics, and infrared spectra of cadmium and zinc halide derivatives

1970 ◽  
Vol 48 (17) ◽  
pp. 2656-2661 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Model Equation ◽  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Frequency Region ◽  
First Order ◽  
Calorimetric Measurements ◽  
Infrared Spectral ◽  
Hydroxy Compounds ◽  
Kinetics Of

The thermal analyses of Cd2(OH)3X type of basic halides reveal that the decomposition occurs via a two-step dehydroxylation pattern, yielding CdOHX as an intermediate product after the initial mode. These results suggest that Cd2(OH)3X is an addition compound of the hydroxide and the 1:1 hydroxy-halide, i.e. Cd(OH)2•CdOHX. Calorimetric measurements along with related enthalpy values for the decomposition reaction are given.The kinetics of thermal decomposition of the compounds are classified into two main groups: (i) two-dimensional contracting plate model equation and (ii) first-order rate law.The infrared spectral data of thirteen Cd and Zn basic halides in the frequency region 4000–250 cm−1 are presented with their assignments.

Studies on Metal Hydroxy Compounds. XIII. Thermal Analyses and Decomposition Kinetics of Hydroxystannates of Bivalent Metals

1971 ◽  
Vol 49 (17) ◽  
pp. 2813-2816 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Order Reaction ◽  
First Order ◽  
Calorimetric Measurements ◽  
Bivalent Metals ◽  
Hydroxy Compounds ◽  
Kinetics Of ◽  
Subsequent Decomposition

The thermal analyses of hexahydroxystannates of bivalent metals of the type Me[Sn(OH)6], where Me = Zn, Co, Cu, Ni, Mn, Ca, Mg, Cd, Sr, reveal that the primary mode of decomposition occurs by dehydroxylation and subsequent decomposition of the metastannate residue occurs in the Zn, Cu, Mn, Ca, and Mg compounds. Calorimetric measurements along with related enthalpic values for the decomposition reaction are given. The kinetics of thermal decomposition of all compounds studied, except the Cd and Mg analogues, follow first order reaction kinetics up to α ~ 0.9.

Studies on metal hydroxy compounds. XII. Thermal analyses, decomposition kinetics, and infrared spectra of copper basic oxysalts

1970 ◽  
Vol 48 (22) ◽  
pp. 3510-3519 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Thermal Analyses ◽  
Three Dimensional ◽  
Decomposition Reaction ◽  
Sphere Model ◽  
First Order ◽  
Calorimetric Measurements ◽  
Infrared Spectral ◽  
Anionic Species ◽  
Hydroxy Compounds ◽  
Kinetics Of

The thermal analyses of copper basic oxysalts of the type Cu2(OH)2XOy, where X = S, C, Cl, Br, I, N, HC and y = 4, 3, or 2 reveal that decomposition occurs, in most cases, by dehydroxylation with concomitant disproportionation of the oxysalt. An outstanding exception to this pattern of decomposition is the basic sulfate. Calorimetric measurements along with related enthalpic values for the decomposition reaction are given.The kinetics of thermal decomposition of the compounds are classified into three main categories: (i) three-dimensional contracting sphere model, (ii) first-order rate, and (iii) nucleation controlled rate processes.The infrared spectral data of nine copper basic oxycompounds in the frequency region 4000–250 cm−1 are presented with their assignments. The fundamental infrared inactive modes of the anionic species SO42−, NO3−, etc. become active by the presence of the copper hydroxide ligand indicating a lowering of symmetry in the anion.

Studies on metal hydroxy compounds. X. Thermal analyses, decomposition kinetics, and infrared spectra of lead halide (Cl, Br, I) derivatives

1970 ◽  
Vol 48 (16) ◽  
pp. 2617-2622 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco ◽  
M. Badri
Keyword(s):  
Infrared Spectra ◽  
Rate Equation ◽  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Diffusion Type ◽  
Type Rate ◽  
Hydroxy Compounds ◽  
Kinetics Of ◽  
Lead Halide ◽  
Order Rate Equation

The thermal analyses, thermogravimetry (TG), and differential thermal analysis (DTA) of PbOHCl, PbOHBr, and PbOHI reveal that the initial mode of decomposition is via dehydroxylation. Calorimetric measurements along with related enthalpy values for the decomposition reaction are given.The infrared spectra of these compounds are interpreted in terms of folded bands of (PbOH+)n tied together by halide ions consistent with their crystal structures.The kinetics of thermal decomposition of lead hydroxyhalides follow a diffusion-type rate equation which is in contrast to the simple first-order rate equation observed for most Cd, Zn, and Cu compounds. These two distinct rates are interpreted in terms of mobile OH or H species in the dehydroxylation step.

Metal Halide Ammines. 1. Thermal Analyses, Calorimetry, and Infrared Spectra of Cadmium Halide (Cl, Br, I) Derivatives

1971 ◽  
Vol 49 (23) ◽  
pp. 3831-3835 ◽  
Author(s):  
K. C. Patil ◽  
E. A. Secco
Keyword(s):  
Spectral Data ◽  
Infrared Spectra ◽  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Metal Halide ◽  
Calorimetric Measurements ◽  
Infrared Spectral

The thermal analyses of cadmium halide hexammines reveal that decomposition occurs by loss of ammonia via the diammine and the monoammine. Calorimetric measurements along with related enthalpic values for the intermediate stable stages of the decomposition reaction are given.The infrared spectral data of the diammines and monoammines are presented with their assignments.

Thermal Decomposition Kinetics of Flame Retardant Polybutylene Terephthalate Matrix Composites

2019 ◽  
Vol 956 ◽  
pp. 181-191
Author(s):  
Jian Lin Xu ◽  
Bing Xue Ma ◽  
Cheng Hu Kang ◽  
Cheng Cheng Xu ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Flame Retardant ◽  
Mass Loss Rate ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
Polybutylene Terephthalate ◽  
Kinetics Of

The thermal decomposition kinetics of polybutylene terephthalate (PBT) and flame-retardant PBT (FR-PBT) were investigated by thermogravimetric analysis at various heating rates. The kinetic parameters were determined by using Kissinger, Flynn-Wall-Ozawa and Friedman methods. The y (α) and z (α) master plots were used to identify the thermal decomposition model. The results show that the rate of residual carbon of FR-PBT is higher than that of PBT and the maximum mass loss rate of FR-PBT is lower than that of PBT. The values of activation energy of PBT (208.71 kJ/mol) and FR-PBT (244.78 kJ/mol) calculated by Kissinger method were higher than those of PBT (PBT: 195.54 kJ/mol) and FR-PBT (FR-PBT: 196.00 kJ/mol) calculated by Flynn-Wall-Ozawa method and those of PBT and FR-PBT (PBT: 199.10 kJ/mol, FR-PBT: 206.03 kJ/mol) calculated by Friedman methods. There is a common thing that the values of activation energy of FR-PBT are higher than that of PBT in different methods. The thermal decomposition reaction models of the PBT and FR-PBT can be described by Avarami-Erofeyev model (A1).

Fire Performances, Hot Properties and Decomposition Kinetics of Sb2O3/DBDPE/RTV

2012 ◽  
Vol 560-561 ◽  
pp. 117-121
Author(s):  
Juan Juan Wang ◽  
Wen Xing Li ◽  
La Jun Feng
Keyword(s):  
Least Squares ◽  
Flame Retardant ◽  
Decomposition Reaction ◽  
Decomposition Temperature ◽  
Decomposition Kinetics ◽  
Rate Equations ◽  
Fire Performance ◽  
Linear Least Squares ◽  
Flame Retardant Property ◽  
Kinetics Of

Fire and hot properties of title composite were taken by the method of vertical burning, OI, and TG. Fire performance experiments demonstrated that the scale of flame retardant property of Sb2O3/ DBDPE/RTV was FV-0, OI was 46. Hot decomposition temperature is about 400 oC to 520 oC with the amount of 20wt% as additives. The kinetic parameters of the decomposition reaction of the title composite have been studied by means of DSC. The data are fitted to the integral, differential and exothermic rate equations by linear least-squares, iterative, combined dichotomous and least-squares methods, respectively. The study leads the reader to the conclusion that the empirical kinetic model functions in differential form, the values of and of this reaction were , -1857.20 kJ/mol and 244.9 s-1 respectively. Sb2O3/ DBDPE are a kind of flame retardant which own its flame retardant function to higher activation energy but the release of halogen. It is a usable retardant during the lifetime.

scholarly journals INFLUENCE OF TEMPERATURE AND PH ON THE DECOMPOSITION KINETICS OF PERACETIC ACID IN AQUEOUS SOLUTIONS

2014 ◽  
Vol 44 (3) ◽  
pp. 195-201
Author(s):  
L. KUNIGK ◽  
S. P. GALIZIA ◽  
R.T. K. SHIKISHIMA ◽  
R. GEDRAITE ◽  
C. H. JURKIEWICZ
Keyword(s):  
Activation Energy ◽  
Aqueous Solutions ◽  
Peracetic Acid ◽  
Food Industry ◽  
Decomposition Kinetics ◽  
Order Reaction ◽  
Influence Of Temperature ◽  
First Order ◽  
All Solutions ◽  
Kinetics Of

Peracetic acid (PAA) is a strong oxidant used by the food industry as a sanitizer, in medical area as a disinfectant and by the textiles and paper industries as a bleacher. Its decomposition rate is an important parameter in these applications. The main purpose of this paper is to study the decomposition kinetics of PAA between 25 and 45 °C in solutions with pH 3.11, 5.0 and 7.0. The decomposition of PAA is a first-order reaction for all solutions and temperatures studied. The rate constants were between 2.08·10-3 and 9.44·10-3 h-1 (pH 3.11), between 2.61·10-3 and 16.69·10-3 h-1 (pH 5.0) and between 7.50·10-3 and 47.63·10-3 h-1 (pH 7.0). The activation energy of PAA decomposition in aqueous solutions are 58.36 and 72.89 kJ·mol-1 when pH was 3.11 and 5.0, respectively.

scholarly journals Non-isothermal decomposition kinetics of magnesite

Cerâmica ◽  
2007 ◽  
Vol 53 (327) ◽  
pp. 284-287 ◽  
Author(s):  
S. Maitra ◽  
S. Mukherjee ◽  
N. Saha ◽  
J. Pramanik
Keyword(s):  
Kinetic Parameters ◽  
Thermo Gravimetric Analysis ◽  
Isothermal Condition ◽  
Kinetic Mechanism ◽  
Decomposition Reaction ◽  
Magnesium Carbonate ◽  
Decomposition Kinetics ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Kinetics Of

Kinetics of thermal decomposition of Indian magnesite was studied by thermo-gravimetric analysis under non-isothermal condition. Coats and Redfern Integral approximation method was used to determine the kinetic parameters. Using the kinetic parameters different kinetic functions were analyzed with the experimental data to ascertain the decomposition mechanism of magnesium carbonate and it was observed that the decomposition reaction followed a contracting sphere kinetic mechanism.

Kinetics of Reactions of 8-Quinolinol and Acetate with Hydroxyaluminum Species in Aqueous Solutions. 1. Polynuclear Hydroxyaluminum Cations

1971 ◽  
Vol 49 (10) ◽  
pp. 1683-1687 ◽  
Author(s):  
R. C. Turner ◽  
Wan Sulaiman
Keyword(s):  
Acetic Acid ◽  
Rate Constant ◽  
Empirical Equation ◽  
Decomposition Reaction ◽  
Order Rate Constant ◽  
Acetate Concentration ◽  
First Order ◽  
Order Rate ◽  
Pseudo First Order ◽  
Kinetics Of

The effect of varying 8-quinolinol and acetate concentration on the rate of decomposition of poly-nuclear hydroxyaluminum cations was studied. It was found that the concentration of the undissociated 8-quinolinol and acetic acid molecules determined the magnitude of the first order rate constant for the decomposition of the polynuclear hydroxyaluminum cations, except when the acetate concentrations were relatively high. With high acetate concentrations, it appeared that polynuclear acetate species were involved in the reactions. An empirical equation was developed showing the effect of 8-quinolinol and acetic acid molecule concentrations on the pseudo first order rate constant for the decomposition reaction.

Study of NH4EuF4 in solid state reaction Eu2O3–NH4F. Thermal analyses, calorimetry, and decomposition kinetics

1977 ◽  
Vol 55 (14) ◽  
pp. 2628-2630 ◽  
Author(s):  
Krishnan Rajeshwar ◽  
Etalo A. Secco
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Solid State Reaction ◽  
Thermal Analyses ◽  
Decomposition Kinetics ◽  
X Ray ◽  
Kinetics Of Thermal Decomposition ◽  
Heat Of Decomposition ◽  
Kinetics Of

The solid state reaction Eu2O3–NH4F leading to the formation of NH4EuF4 was studied by thermal analyses and X-ray diffraction.The heat of decomposition of NH4EuF4 and the kinetics of thermal decomposition of NH4EuF4 are reported.

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