Applications of Kinetic Methods in Thermal Analysis: A Review

Zhang, Xin

doi:10.30919/es8d1132

Cited by 25 publications

(30 citation statements)

References 91 publications

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“…In a previous work, Gama and co-workers [13] studied the curing process of castor oil-based PU adhesives by differential scanning calorimetry (DSC) using the two most known approaches, the Kissinger [42] and the Ozawa [43] methods. Both methods are rapid, easy to use and depend on a series of experiments based on heating samples at several different heating rate [44]. Kinetic parameters, such as the activation energy (E a ) of the cure and the degree of cure (or conversion, α), were determined from nonisothermal measurements using different heating rates (β).…”

Section: Introductionmentioning

confidence: 99%

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Lignosulfonate-Based Polyurethane Adhesives

et al. 2021

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The feasibility of using lignosulfonate (LS) from acid sulphite pulping of eucalyptus wood as an unmodified polyol in the formulation of polyurethane (PU) adhesives was evaluated. Purified LS was dissolved in water to simulate its concentration in sulphite spent liquor and then reacted with 4,4′-diphenylmethane diisocyanate (pMDI) in the presence or absence of poly(ethylene glycol) with Mw 200 (PEG200) as soft crosslinking segment. The ensuing LS-based PU adhesives were characterized by infrared spectroscopy and thermal analysis techniques. The adhesion strength of new adhesives was assessed using Automated Bonding Evaluation System (ABES) employing wood strips as a testing material. The results showed that the addition of PEG200 contributed positively both to the homogenization of the reaction mixture and better crosslinking of the polymeric network, as well as to the interface interactions and adhesive strength. The latter was comparable to the adhesive strength recorded for a commercial white glue with shear stress values of almost 3 MPa. The optimized LS-based PU adhesive formulation was examined for the curing kinetics following the Kissinger and the Ozawa methods by non-isothermal differential scanning calorimetry, which revealed the curing activation energy of about 70 kJ·mol−1.

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Section: Introductionmentioning

confidence: 99%

“…when the curing rate (β) is increased, the peak temperature (T p ) shifts to a higher temperature range, and this can be used to calculate E a , using methods such as the Kissinger method or Ozawa method [44], according to Equations ( 3) and (4), respectively.…”

Section: Introductionmentioning

confidence: 99%

Lignosulfonate-Based Polyurethane Adhesives

et al. 2021

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“…At present, non-isothermal kinetics has become the focus of attention, with a number of review papers published [82][83][84][85], but with almost none of them questioning the influence of thermal inertia as one of the missing key factors. Thermo-analytical methods that actually deal with heat transfer and the inclusion and description of this transfer in the standard thermo-analytical literature are so far mostly absent.…”

Section: Discussionmentioning

confidence: 99%

Dynamic Character of Thermal Analysis Where Thermal Inertia Is a Real and Not Negligible Effect Influencing the Evaluation of Non-Isothermal Kinetics: A Review

Šesták

2021

Thermo

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The development of instrumentation has allowed thermal analysis to become a widely used method not only in calorimetry but also in the field of non-isothermal kinetics that, however, provides a simplified philosophy of measurements. From the beginning, a methodology is used describing the course of reaction in a simplified temperature regime measured in an inert sample. In a most common case of DTA, the degree of reaction is subtracted from the partial areas of the as-cast peak in the unified mode of the peak linear background. Usually, the effect of thermal inertia, resulting from the reality of heat transfer and changing the peak background to a non-linear s-shaped form, is not incorporated. Therefore, the question of whether or not to include this effect of thermal inertia has become a current underlying problem of thermo-analytical kinetics. The analysis of the rectangular input heat pulses and their DTA responding fundamentally point to the need to include it thus becoming essential and not negligible. In the case of parallel evaluations, the effect of inertia can be partially compensated for each other such as in the Kissinger evaluation method. The study presents a broad overview of the thermo-analytical methodology used and points to the often-neglected literature. However, standard mainstream kinetics procedures need be fixed, and an improved solution found to account for the effect of heat transfer and dissipation, which is becoming the focus of thermal analysis methods of future and also the intention of this review.

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“…The liquid phase formation and distribution were monitored in quenching dilatometer experiments with defined heating up to different temperatures (1120 • C, 1180 • C, 1250 • C, 1300 • C) and subsequent quenching. From these measurements, through Kissinger plots, the relationship between a reaction peak and the heating rate can be described [13,19]. Usually this is done with peaks from DTA measurements [13,20,21].…”

Section: Influence Of the Heating Rate On The Melting Processmentioning

confidence: 99%

“…"T max is by definition a function of the heating rate only" [22]. For Kissinger Plots, it has to be assumed that the melting reaction of the MA obeys a first-order law [13,19,22]. In this case, at constant temperature Equation (1) can be described.…”

Section: Influence Of the Heating Rate On The Melting Processmentioning

confidence: 99%

Transient Liquid Phase Sintering of PM Steel—A Matter of the Heating Rate

Geroldinger¹,

Calderon²,

Gierl‐Mayer³

et al. 2021

Metals

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Powder metallurgy (PM) offers several variants to introduce alloying elements for establishing the desired final composition. One route is the master alloy (MA) approach. The composition and the elements contained in the MA can be adjusted to obtain a liquid phase that penetrates through the interconnected pore network and thus enhances the distribution of the alloying elements and the homogenization of the microstructure. Such a liquid phase is often of a transient character, and therefore the amount of liquid formed and the time the liquid is present during the sintering are highly dependent on the heating rates. The heating rate has also an impact on the reaction temperatures, and therefore, by properly adjusting the heating rate, it is possible to sinter PM-steels alloyed with Fe-Cr-Si-C-MA at temperatures below 1250 °C. The present study shows the dependence of the melting regimes on the heating rate (5, 10, 20, 120 K/min) represented by “Kissinger plots”. For this purpose, liquid phase formation and distribution were monitored in quenching dilatometer experiments with defined heating up to different temperatures (1120 °C, 1180 °C, 1250 °C, 1300 °C) and subsequent quenching. Optimum sintering conditions for the materials were identified, and the concept was corroborated by C and O analysis, CCT diagrams, metallographic sections, and hardness measurements.

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Applications of Kinetic Methods in Thermal Analysis: A Review

Cited by 25 publications

References 91 publications

Lignosulfonate-Based Polyurethane Adhesives

Lignosulfonate-Based Polyurethane Adhesives

Dynamic Character of Thermal Analysis Where Thermal Inertia Is a Real and Not Negligible Effect Influencing the Evaluation of Non-Isothermal Kinetics: A Review

Transient Liquid Phase Sintering of PM Steel—A Matter of the Heating Rate

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