Simultaneous use of isothermal, nonisothermal, and constant rate thermal analysis (CRTA) for discerning the kinetics of the thermal dissociation of smithsonite

Gotor, F.J.; Macı́as, M.; Ortega, Abraham Barrero; Criado, J. M.

doi:10.1002/(sici)1097-4601(1998)30:9<647::aid-kin6>3.0.co;2-s

Cited by 33 publications

(22 citation statements)

References 18 publications

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“…The 31 P chemical shift was referred to H 3 PO 4 at 0 ppm. 13 C NMR experiment was conducted on the same spectrometer as above operating at 100.6 MHz, at ν rot = 10 kHz with a 4 ms pulse length (corresponding to a π/2 flip angle), a rd of 10 s and 4096 transients. High-power 1 H decoupling and 1 H-13 C cross-polarization (CP) were used (acquisition with a contact time of 1 ms).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

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Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

Bourbigot¹,

Sarazin²,

Samyn³

et al. 2019

Polymer Degradation and Stability

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The concept of intumescence was applied to flame retard ethylene vinyl acetate copolymer (EVA). The paper examines two types of intumescence based on expandable graphite (EG, physical expansion) and on modified ammonium polyphosphate (AP760, chemical expansion). The incorporation of expandable graphite (EG) at relatively low loading (10 wt%) in EVA permits the reduction up to 65% of peak of heat release rate (pHRR) measured by cone calorimetry. The mode of action occurs via the formation of an expanded carbonaceous layer acting mainly as heat barrier limiting heat and mass transfer as evidenced by the temperature measurement as a function of time during cone calorimetry. The incorporation of small amount of ZnCO 3 in EVA-AP760 enhances strongly the performance: pHRR was not reduced using the sole AP760 while it is decreased by 54% when only 2 wt% of AP760 is substituted by ZnCO 3. A strong synergistic effect was therefore observed. Solid state NMR of 31 P and 13 C on cone residues prepared at different characteristic times evidenced the mechanism involved is the reinforcement of the protective char by the formation of phosphate glass limiting the creation of cracks and increasing the char strength.

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Section: Accepted Manuscriptmentioning

confidence: 99%

“…The heat flux was shut down and the samples were taken out at the selected time. They were then characterized by CP/DD-MAS 13 C NMR ( Fig. 8) and DD-MAS 31 P NMR (Fig.…”

Section: Mechanical Resistance Of Intumescent Charmentioning

confidence: 99%

Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

Bourbigot¹,

Sarazin²,

Samyn³

et al. 2019

Polymer Degradation and Stability

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“…2 by A 2.5 , namely Avrami‐Erofeev model for m = 2.5) with the activation parameters E = 159 ± 2 kJ mol −1 and A = (1.1 ± 0.4) × 10 12 min −1 . The procedure for f (α) discrimination used by Perez‐Maqueda et al 2 belongs to the procedures which suppose the consideration of a set of differential functions of conversion 3–6. There is a possibility that the true f (α) does not belong to the set of preestablished differential functions of conversion.…”

Section: Introductionmentioning

confidence: 99%

On the evaluation of the nonisothermal kinetic parameters of (GeS₂)_0.3(Sb₂S₃)_0.7 crystallization using the IKP method

Budrugeac

Criado

Gotor

et al. 2004

Int J of Chemical Kinetics

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The isoconversional method suggested by Friedman and the invariant kinetic parameters method (IKP) were used in order to examine the kinetics of the nonisothermal crystallization of (GeS 2 ) 0.3 (Sb 2 S 3 ) 0.7 . The objective of the paper is to show the usefulness of the IKP method both for determining the activation parameters as well as the model of the investigated process. It was shown that the kinetic triplet [(E, A, f (α), where E is the activation energy, A is the preexponential factor, and f (α) is the differential function of conversion], which results through the application of the IKP method, depends on the set of kinetic models considered. For different sets of kinetic models, proportional values of f (α) are obtained. A criterion for the selection of this set, the use of which lead to the true kinetic triplet corresponding to the analyzed process (E = 163.2 kJ mol −1 ; A = 2.47 × 10 12 min −1 and the Avrami-Erofeev model, A m , for m = 2.5-2.6 was suggested. C

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“…It has also been used for the thermal analysis of a wide range of reactions, such as dehydrations and dehydroxylations, denitrations, and decarbonations . Moreover, CRTA experiments have been included in kinetic studies of thermal decomposition of materials, mainly carbonates, polymers, polymer nanocomposites, but also other compounds, to clarify the kinetic model followed by the reactions. Interestingly, SCTA has also applications in quantitative characterization, and even has been used in sintering studies .…”

Section: Introductionmentioning

confidence: 99%

A Promising approach to the kinetics of crystallization processes: The sample controlled thermal analysis

et al. 2016

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Constant Rate Thermal Analysis (CRTA) method implies controlling the temperature in such a way that the reaction rate is maintained constant all over the process. This method allows determining simultaneously both the kinetic parameters and the kinetic model from a single experiment as the shape of the CRTA α‐T curves strongly depends on the kinetic model. CRTA method has been developed in the market only for thermogravimetric and thermodilatometric systems and, therefore, its use has been limited until now to the kinetic study of processes involving changes in mass or size of the samples, respectively. To overcome this obstacle, a method has been developed in this work for using the DSC signal for controlling the process rate in such a way that CRTA would be applied to the kinetic analysis of either phase transformations or crystallizations. The advantages of CRTA for performing the kinetics of crystallization processes have been here successfully demonstrated for the first time after selecting the crystallization of zirconia gel as test reaction.

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Simultaneous use of isothermal, nonisothermal, and constant rate thermal analysis (CRTA) for discerning the kinetics of the thermal dissociation of smithsonite

Cited by 33 publications

References 18 publications

Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

On the evaluation of the nonisothermal kinetic parameters of (GeS₂)_0.3(Sb₂S₃)_0.7 crystallization using the IKP method

A Promising approach to the kinetics of crystallization processes: The sample controlled thermal analysis

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Simultaneous use of isothermal, nonisothermal, and constant rate thermal analysis (CRTA) for discerning the kinetics of the thermal dissociation of smithsonite

Cited by 33 publications

References 18 publications

Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

Intumescent ethylene-vinyl acetate copolymer: Reaction to fire and mechanistic aspects

On the evaluation of the nonisothermal kinetic parameters of (GeS2)0.3(Sb2S3)0.7 crystallization using the IKP method

A Promising approach to the kinetics of crystallization processes: The sample controlled thermal analysis

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Product

Resources

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On the evaluation of the nonisothermal kinetic parameters of (GeS₂)_0.3(Sb₂S₃)_0.7 crystallization using the IKP method