Galukhin, Andrey Vladimirovich

Bolmatenkov D.N., Nizamov I.I., Aleshin R.P., Galukhin A.V., Yagofarov M.I., Solomonov B.N.

Two n-alkyl azides, n-tetradecyl- and n-octadecyl azides, were synthesized and characterized by differential scanning calorimetry and fast scanning calorimetry. Based on the experiments performed, the enthalpies and temperatures of solid-solid transitions and fusion, condensed phase heat capacities, vapor pressures above the liquids, and vaporization enthalpies were obtained, and temperature limits of stability were determined. Combining the newly obtained and existing literature data on the vaporization characteristics of n-alkyl azides, the linear dependences of the vaporization enthalpy and the natural logarithm of vapor pressure on the chain length were derived at 298.15 K and the p-T properties of unstudied members of homologous series were predicted.

Galukhin A.

The present paper proposes the isoconversional approach to a quantitative assessment of the reactivity in elementary and complex reactions studied by thermal methods under non-isothermal conditions. The focus is on the processes studied at a constant heating rate as the most common mode used in thermal analysis. The accuracy of the proposed approach is tested on simulated data for elementary reactions, whereas its practical application is demonstrated on few experimental examples. The effect of experimental uncertainties on the precision of the introduced reactivity factors is also considered.

Galukhin A., Kachmarzhik A., Rodionov A., Mamin G., Gafurov M., Vyazovkin S.

A detailed investigation of the liquid-state polymerization of diacetylenes by calorimetric (DSC) and spectroscopic (in situ EPR) thermal analysis techniques is performed. Isoconversional kinetic analysis of the calorimetric data reveals that liquid-state polymerization is governed by a well-defined rate-limiting step as evidenced by a nearly constant isoconversional activation energy. By comparison, solid-state polymerization demonstrates isoconversional activation energy that varies widely, signifying multistep kinetics behavior. Unlike the solid-state reaction that demonstrates an autocatalytic behavior, liquid-state polymerization follows a rather unusual zero-order reaction model as established by both DSC and EPR data. Both techniques have also determined strikingly similar Arrhenius parameters for liquid-state polymerization. Relative to the solid-state process, liquid-state polymerization results in quantitative elimination of the p-toluenesulfonate group and the formation of p-toluenesulfonic acid and a polymeric product of markedly different chemical and phase composition.

Galukhin A., Aleshin R., Nosov R., Vyazovkin S.

Two flexible α-azide-ω-alkynes differing in the length of the hydrocarbon spacers (C8 vs. C12) between functional groups are synthesized. Their bulk polymerization kinetics is studied by differential scanning calorimetry (DSC) and parameterized with the aid of isoconversional methodology. The monomer with a shorter hydrocarbon spacer has somewhat greater reactivity. The effect is traced to a moderate increase in the effective value of the preexponential factor that arises from the fact that the respective monomer has a higher initial molar concentration in itself. The techniques of GPC and NMR provide additional kinetic and mechanistic insights into the studied reaction.

Galukhin A., Aleshin R., Nosov R., Vyazovkin S.

Experimental kinetic study of bulk azide–alkyne cycloaddition reveals the concerted mechanism of the formation of both possible regioisomers.

Galukhin A., Vyazovkin S.

AbstractThis article reviews both time‐honored and most recent studies of the mechanisms and kinetics of cyanate esters polymerization. Different types of processes, including catalytic, non‐catalytic, bulk, solution, and nanoconfined ones are covered. The mechanistic and empirical models suitable for describing the kinetic and diffusion regimes of polymerization are discussed at length. Recent advances in methodology of the analysis of multistep polymerization reactions by means of model‐fitting and isoconversional techniques are considered as applied to cyanate esters. The importance of the calorimetric measurements in polymerization studies is emphasized.

Galukhin A., Nosov R., Taimova G., Shulyatiev A., Nikolaev I., Islamov D., Vyazovkin S.

• Phenol-catalyzed cyclotrimerization of cyanate ester is studied • DSC, combustion calorimetry, and chromatography are employed • Kinetics is analyzed by isoconversional methodology • Important kinetic and mechanistic insights are obtained Differential scanning and combustion calorimetry in combination with isoconversional methodology and chromatography are applied to acquire kinetic and mechanistic insights into the reaction of phenol-catalyzed cyclotrimerization of cyanate ester. The only detectable reaction intermediate is found to be imidocarbonate, which is demonstrated to form in an irreversible manner. Isoconversional analysis indicates that the overall reaction kinetics at its early and late stages is respectively controlled by the irreversible formation of imidocarbonate ( E a ≈40 kJ mol −1 ) and a reaction of imidocarbonate with cyanate ester ( E a ≈70 kJ mol −1 ). Cyclotrimerization of neat imidocarbonate is analyzed as well. For this reaction, no intermediates are detected. Its overall kinetics is determined to occur as a single autocatalytic step. It is concluded that cyclotrimerization of imidocarbonate does not amount to any significant competition to the reaction between imidocarbonate and cyanate ester.

Nagrimanov R.N., Ibragimova A.R., Buzyurov A.V., Solomonov B.N., Nosov R.V., Nikolaev I.A., Galukhin A.V.

Vyazovkin S., Achilias D., Fernandez-Francos X., Galukhin A., Sbirrazzuoli N.

• Recommendations are provided for kinetic analysis of thermal polymerization. • Main focus is on analysis of DSC measurements. • Multi-step nature of polymerization kinetics is emphasized. • Model-fitting, isoconversional, and deconvolution analyses are discussed. • Specific advices are offered for efficient usage of each analysis. The present recommendations have been developed by the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC). The recommendations provide guidance on kinetic analysis of thermal polymerization, which incorporates both linear and crosslinking polymerization (curing). The focus is on treating the kinetics as measured by differential scanning calorimetry (DSC). The recommendations discuss basic reaction mechanisms and emphasize the multi-step nature of the polymerization kinetics. An overview of mechanistic and phenomenological models is provided for polymerization controlled by reaction kinetics and diffusion. Three different approaches to evaluation of kinetic parameters (activation energy, preexponential factor, reaction model) for individual steps are considered. These approaches comprise model-fitting, isoconversional, and deconvolution analyses. Practical advices are offered for effective usage of each approach. Attention is paid to the typical problems and to the ways of addressing them. The recommendations are intended to assist with efficiently conducting kinetic analysis and interpreting its results.

Galukhin A., Nikolaev I., Nosov R., Vyazovkin S.

This study highlights the value of nonisothermal kinetic methods in selecting temperature conditions for the isothermal preparation of microporous polymeric materials. A dicyanate ester is synthesized and the kinetics of its polymerization in diphenyl sulfone are studied by calorimetry under nonisothermal conditions. The kinetics are analyzed by a model-based approach, using the Kamal model, as well as by a model-free approach, using an advanced isoconversional method. Both approaches correctly predict the time to completion of polymerization at a given temperature. The material prepared independently at the predicted temperature is characterized by electron microscopy and CO2 adsorption measurements and is confirmed to possess a microporous structure with a multimodal distribution of micropores with two major maxima at ~0.5 and 0.8 nm.

Lapuk S.E., Ponomareva M.A., Galukhin A.V., Mukhametzyanov T.A., Schick C., Gerasimov A.V.

The stability of glassy materials, including polymer-based ones, is one of the important subjects of material science and technology. This interest is due to the dependence of the properties of the end products, based on glassy materials, on the processing and storage conditions. In particular, the application of amorphous solid dispersions based on polymer excipients requires an understanding of the kinetics of the formation and the physical aging of the glassy state. The kinetic parameters of the glass transition of polyvinylpyrrolidone, a widely used polymer in the pharmaceutical industry, were determined in the present work using fast scanning calorimetry. The dependencies of the Vogel temperature and the kinetic fragility on the molecular mass of the polymer were determined, as well as the apparent activation energy of the physical aging process, which changes from 256 kJ·mol–1 in the case of polyvinylpyrrolidone with a molecular mass of 3500 g·mol–1 to 565 kJ·mol–1 in the case of polyvinylpyrrolidone with a molecular mass of 1,300,000 g·mol–1. The results of the current work can be used to optimize the processing of polymer-based glassy materials to obtain the desired properties for application in different fields of technology, including pharmaceuticals.

Galukhin A., Nosov R., Nikolaev I., Kachmarzhik A., Aleshin R., Islamov D., Vyazovkin S.

• New adamantane-based dicyanate ester is synthesized. • DSC polymerization kinetics is studied by isoconversional and model based methods. • Polymer is characterized by TGA, TMDSC, and TMA. • Improvement in thermal properties and kinetic changes are linked to structure. A new adamantane-based dicyanate ester has been synthesized. The kinetics of its thermal polymerization is studied by means of conventional and temperature-modulated differential scanning calorimetry. The kinetics is analyzed comprehensively by a combination of an advanced isoconversional and model-fitting method. Polymerization proceeds via transition from a kinetic- to diffusion-control regime, which becomes operative at the later stages of the process. The kinetically-controlled regime manifests itself as a quasi-one-step auto-catalytic reaction. A contribution of diffusion to the overall kinetic is accounted for by means of the Fournier model. The polymerization product possesses excellent thermal properties (the glass transition temperature of ∼370 °C and 5% mass loss temperature of ∼480 °C), which makes it a promising candidate for application in hot-section components for aerospace and military industry.

GALUKHIN A., MALAKHOVA E., PONIZOVKINA I.

Scientific theories and methods developed within the framework of quantum and relativistic physics are the most representative paradigmatic instantiations of non-classical science. The profile of non-classical science is exposed through the analysis of a set of epistemic ideals and methodological principles. The adoption of the principle of operational relativity of phenomenal descriptions showed that a reference to the means of observation had become an intrinsic part of scientific description strategies. The transformation of the concept of objectivity can be seen in a specific combination of operationalism with interactional phenomenalism and constructivism. The introduction of the principle of complementarity marked the deviation from the standards of a monologic and linear description of the objects under study. This principle provides the operational basis for the integration of different parts of our knowledge with regard to non-trivial cognitive situations featured by the indeterminacy relations. Another prominent methodological trend is the reconsideration of the value of strict deterministic explanation strategies in favour of probabilistically oriented approaches. Scientists have encountered a new class of regularities that are typically analysed in terms of various types of statistical and non-causal determination. Nevertheless, it would be wrong to assume that any probabilistic account of natural phenomena implies indeterminism.

Vyazovkin S., Galukhin A.

Ozawa has modified the Avrami model to treat non-isothermal crystallization kinetics. The resulting Ozawa–Avrami model yields the Avrami index (n) and heating/cooling function (χ(T)). There has been a number of recent applications of the Ozawa–Avrami model to non-isothermal crosslinking polymerization (curing) kinetics that have determined n and have used χ(T) in place of the rate constant (k(T)) in the Arrhenius equation to evaluate the activation energy (E) and the preexponential factor (A). We analyze this approach mathematically as well as by using simulated and experimental data, highlighting the following problems. First, the approach is limited to the processes that obey the Avrami model. In cases of autocatalytic or decelerating kinetics, commonly encountered in crosslinking polymerizations, n reveals a systematic dependence on temperature. Second, χ(T) has a more complex temperature dependence than k(T) and thus cannot produce exact values of E and A via the Arrhenius equation. The respective deviations can reach tens or even hundreds of percent but are diminished dramatically using the heating/cooling function in the form [χ(T)]1/n. Third, without this transformation, the Arrhenius plots may demonstrate breakpoints that leads to questionable interpretations. Overall, the application of the Ozawa–Avrami model to crosslinking polymerizations appears too problematic to be justified, especially considering the existence of well-known alternative kinetic techniques that are flexible, accurate, and computationally simple.

Galukhin A., Nikolaev I., Nosov R., Islamov D., Vyazovkin S.

The mechanism of thermally stimulated polymerization of tricyanate ester remains the same in solution as in the melt, but Arrhenius parameters of the rate-limiting reaction are significantly affected by solvation.

Gao C., Xiong R., Guo J., Kiyingi W., Song H., Wang L., Zhang W., Chen X.

Lei Z., Jin M., Lei Y., Cheng D., Sun T.

Li B., Liu Y., Li B., Zhang J., Wang J., Chai Y., Nan J., Fu X., Li Z.

Kotp M.G., Mohamed M.G., Mousa A.O., Kuo S.

Mahmoud T., Sayed M.A., Mubarak M.F., A. R.A.

The increasing demand for heavy crude oil as an alternative to depleting light oil resources has underscored the need for innovative methods to address its high viscosity, which hinders extraction, transportation, and refining. This study introduces a sustainable catalytic cracking method employing hybrid metal oxides derived from oil-contaminated sand to upgrade heavy asphaltic crude oil. The hybrid metal oxides serve as efficient catalysts, significantly reducing the viscosity of crude oil by up to 73.3% compared to thermal treatment alone, while lowering asphaltene, sulfur, and resin contents by 39.5%, 33.2%, and 26%, respectively upon using 0.5% additives at 200 °C for two hours. Characterization techniques, including FTIR, XRD, BET, and XRF, validated the catalyst’s structural and chemical properties, revealing its pivotal role in enhancing rheological behavior and promoting hydrocarbon bond breaking. These findings demonstrate the unique potential of valorizing waste materials and upgrading heavy crude oils, presenting a cost-effective and environmentally friendly approach to addressing industry challenges.

Mukhametzyanov T., Nazimov S., Schick C.

Zhang G., Sun F., Zhao J., Sun B., Xu W., Yang Z.

Ostojić S., Micić D., Dukić J., Sabljak I., Akyüz A., Ersus S., Režek Jambrak A.

Thermal characteristics of dried sugar beet pulp, leaves and leaf fractions obtained after extraction: fibrous leaf pulp and fibre rich leaf fraction, were investigated by differential scanning calorimetry and thermogravimetry. The sugar beet samples showed a similar thermal behaviour associated with a similar composition. Two endotherms are found on the differential scanning calorimetry curves. First one in the temperature range 31–153 °C and the second from 150–160 °C. Thermal degradation kinetics was studied by thermogravimetric analysis. Four degradation stages were observed within the temperature range 25–700 °C. The kinetic parameters of the degradation, obtained by Ortega and Friedman non-isothermal isoconversional methods did not significantly differ between models: Ea-activation energy at a conversion degree 0.1–0.9 ranged 50–200 kJ/mol; lnA- the natural logarithm of the pre-exponential factor 8–48; kp1-thermal degradation rate constant at a conversion extent of 0.5 ranged of 0.19–2.55 min−1. Constant rate of degradation is highest for the sugar beet leaves kp1 (2.58–2.55 min−1), and kp2 (70.1–70.4 min−1). The results obtained are valuable for sugar beet leaf industrial processing. A positive environmental impact is achieved by transforming the waste into high-value food additives.

Asai P., Jordan T., Semeykina V., Tran T., Butt D., Deo M., Zharov I.

Hao Z., Bo F., Wu Y., Cao X.

ABSTRACTEpoxy vitrimers have aroused increasing research attention owing to their stable physicochemical properties, recyclability, and reprocessability, and they even achieve rapid self‐healing by the design of multiple dynamic covalent. However, based on the requirement of optimized curing process, research on cure kinetics of multiple dynamic epoxy vitrimer with flexibility is overtly insufficient, compared with single dynamic epoxy vitrimers. Herein, an amine curing agent with imine group (DN) and epoxy with disulfide and β‐hydroxyl ester groups (EP) were synthesized, respectively, and the thermoset epoxy was fabricated from either diglycidyl ether of bisphenol A (E51) or EP cured with DN. The comparison of E51/DN and EP/DN crosslinked network on cure kinetics, mechanical properties, and self‐healing performance was investigated in detail. The activation energy (E a ) of curing reaction for E51D0.25 was low at 31.79 kJ/mol, while EPD0.25 had a higher E a of 58.81 kJ/mol due to complex reactions. Especially, when the conversion was up to 80%, the E a of EPD0.25 showed a sharp increment due to the combined effect of crosslinked network and reaction of β‐hydroxyl groups. In terms of performance, compared with single dynamic network (E51D0.25), the flexibility, self‐healing, and recyclability of vitrimer were all improved through introduction of triple dynamic bonds.

Cockreham C., Zhang X., Strzelecki A.C., Benmore C., Campe C., Guo X., Rosenberg Y.O., Reznik I.J., Klein-BenDavid O., Lucero D.D., Stauffer P.H., Bussod G.Y., Xu H., Wu D., Boukhalfa H.

Jamali Moghadam Siahkali M., Guigo N., Vincent L., Sbirrazzuoli N.

Nizamov I.I., Bolmatenkov D.N., Yagofarov M.I., Solomonov B.N.

Khelkhal M.A., Ostolopovskaya O.V., Eskin A.A., Vakhin A.V.

Spasennykh M., Shirokova V., Ilmenskii A., Kozlova E., Bulatov T., Goncharova A., Leushina E.

The paper is devoted to kinetic studies of thermal decomposition of organic matter in organic-rich rocks. Kinetic studies are the consisting part of geochemical investigations of source rocks and petroleum systems. The results are required for petroleum generation prediction and assessment of reservoir hydrocarbons quantity and quality using basin modelling. Kinetic data is also applied for simulation of in-situ kerogen conversion and hydrocarbons generation, which are the main processes of thermal methods of enhanced oil recovery (thermal EOR).The paper summarizes fundamental concepts and experimental approaches for kinetic studies of organic matter thermal transformation, it provides an overview of modern methods, equipment and experimental procedures for obtaining bulk and compositional activation energy distributions (spectra) in open and closed systems, and discusses the benefits, limitations, and possible applications of the different methods.The paper presents the scope of experimental procedures, which have been elaborated at Skoltech, and the obtained results: (i) bulk kinetic spectra, which are aimed at express prediction of the total yield of mobile hydrocarbons during kerogen transformation; (ii) compositional kinetic spectra, which considers the amount and composition of hydrocarbon products; (iii) kinetic model of organic matter transformation in a closed system, which considers primary kerogen decomposition and secondary reactions of the hydrocarbons. The kinetic spectra were obtained for various organic-rich rocks collected within the Russian Federation.

Yan Y., Wang Q., Cui M., Bian H., Han Y., Xu J., Zheng F., Guo G.

Primary explosives are essential energy transfer materials in explosive systems. At present, heavy metal-containing materials, such as lead azide (LA), are still the most widely used primary explosives. Copper azide (CA)-based primary explosives are considered as promising replacements for LA. However, there has little advancement in the high initiation performance and high safety of CA-based primary explosives because of the absence of the relevant theories and structural models. Herein, we report [Cu(N3)(2-bmttz)]n 1 with the exceptionally remarkable initiating capability and high safety. Performance tests indicated only 5 mg of 1 can successfully ignite the commercial secondary explosive RDX, as 1/6 priming charge of LA, demonstrating 1 is possibly the most efficient primary explosive known to date. Moreover, 1 possesses the rarely low impact sensitivity (IS = 2.5 J), which is comparable to that of LA and better than most of reported CA-based candidates. Both experimental and theoretical studies have shown that passivation of high-energy primary explosives can be achieved through the coordination between functional ligands and azide ions, in which azide ions without repulsive steric clashes only act as energetic building blocks. This work offers a new insight for designing high performance primary explosives for applications in advanced explosive systems.

Galukhin A., Aleshin R., Nosov R., Vyazovkin S.

Two flexible α-azide-ω-alkynes differing in the length of the hydrocarbon spacers (C8 vs. C12) between functional groups are synthesized. Their bulk polymerization kinetics is studied by differential scanning calorimetry (DSC) and parameterized with the aid of isoconversional methodology. The monomer with a shorter hydrocarbon spacer has somewhat greater reactivity. The effect is traced to a moderate increase in the effective value of the preexponential factor that arises from the fact that the respective monomer has a higher initial molar concentration in itself. The techniques of GPC and NMR provide additional kinetic and mechanistic insights into the studied reaction.

Vyazovkin S., Sbirrazzuoli N.

Providing a minimum of theory, this review focuses on practical aspects of analyzing the kinetics of nonisothermal crystallization as measured with differential scanning calorimetry (DSC). It is noted that kinetic analysis is dominated by approaches based on the Avrami and Arrhenius equations. Crystallization kinetics should not be considered synonymous with the Avrami model, whose nonisothermal applications are subject to very restrictive assumptions. The Arrhenius equation can serve only as a narrow temperature range approximation of the actual bell-shaped temperature dependence of the crystallization rate. Tests of the applicability of both equations are discussed. Most traditional kinetic methods tend to offer very unsophisticated treatments, limited only to either glass or melt crystallization. Differential or flexible integral isoconversional methods are applicable to both glass and melt crystallization because they can accurately approximate the temperature dependence of the crystallization rate with a series of the Arrhenius equations, each of which corresponds to its own narrow temperature interval. The resulting temperature dependence of the isoconversional activation energy can be parameterized in terms of the Turnbull–Fisher or Hoffman–Lauritzen theories, and the parameters obtained can be meaningfully interpreted and used for kinetic simulations.

Galukhin A., Aleshin R., Nosov R., Vyazovkin S.

Experimental kinetic study of bulk azide–alkyne cycloaddition reveals the concerted mechanism of the formation of both possible regioisomers.

Bolmatenkov D.N., Yagofarov M.I., Sokolov A.A., Solomonov B.N.

Vaporization, sublimation and fusion enthalpies of 39 phenol derivatives were thoroughly analyzed using Kirchhoff's and Hess's laws of Thermochemistry to derive the reliable ΔlgH°(298.15 K) values. During the analysis, the correction for non-ideality for the high-temperature vaporization enthalpies was performed. The crystal, liquid and gas heat capacities available from the literature were complemented with the additional experimental measurements of the condensed phases and the computations of the ideal gas properties. Analyzing the available information, we proposed a simple approach for the estimation of the temperature dependence of the vaporization enthalpy of phenol derivatives that showed high accuracy for compounds of various structure.

Kumar V., Lal K., Naveen, Tittal R.K.

The demand for environmental friendly methodologies had shifted the the approach of scientific community for using easy and green reaction conditions instead of using hazardous and harsh reaction conditions. One of the suggested approaches, use of catalyst remained prime choice for harsh free green reaction. The difficulty in the separation of homogeneous catalyst from reaction product increased the attention of chemists for heterogeneous catalysts. The present review summarizes some recent important developments in heterogeneous catalysis using “click reaction” for obtaining 1,2,3-triazoles via Cu-catalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC). A vast collection of papers is efficiently grouped into two significant classes to increase readability in easy language. Firstly, the CuAAC reactions, and secondly, other metal-catalyzed azide-alkyne cycloaddition (MAAC) reactions are discussed. The CuAAC reactions are further grouped into two sub-classes of Cu(I)-nanoparticle catalyzed azide-alkyne cycloaddition (Cu-NPs-AAC) and simple Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reactions. In most cases, the formation of 1,4-disubstituted 1,2,3-triazoles, as reported, was conveniently presented with the help of colored schemes.

Bolmatenkov D.N., Notfullin A.A., Yagofarov M.I., Nagrimanov R.N., Italmasov A.R., Solomonov B.N.

In this work, the literature data, experimental measurements and structure–property relationships were combined to obtain reliable vaporization characteristics of the homologous series of linear alkyl phenones. We critically analyzed the available literature vapor pressures and vaporization enthalpies of acetophenone, propiophenone, and heptanophenone, performed vapor pressure measurements of hexano-, octano- (by transpiration method) and octadecanophenone (by TG-FSC method) and established a linear dependence of the enthalpy and Gibbs free energy of vaporization on the chain length. These quantities in combination with the Clarke-Glew equation enable accurate estimation of P – T dependences along the saturation curve. The quantities obtained were verified by comparison between the calculated and experimental data for the less studied homologs and showed quality comparable with the experiment.

Koga N., Vyazovkin S., Burnham A.K., Favergeon L., Muravyev N.V., Pérez-Maqueda L.A., Saggese C., Sánchez-Jiménez P.E.

• Recommendations are collected for the kinetic analysis of thermal decompositions • Basic kinetic procedures are introduced briefly. • Individual thermal decomposition features for different types of materials are discussed separately. • Appropriate kinetic approaches are described for each specific process. • Necessity of the evaluation of the kinetic results is emphasized. In this review article, the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC) delivers a collection of recommendations for the kinetic analysis of thermal decomposition processes. These recommendations specifically focus on the thermal decomposition processes in inorganic, organic, and polymeric materials, as well as biomass and solid fuels. A general introduction to the kinetic analysis of thermal decompositions studied by thermal analysis techniques is followed by individual sections that discuss thermal decomposition of specific classes of materials and respective kinetic approaches. In each section, various kinetic analysis procedures are introduced with regard to specific features of the reactions and explained progressively from simple to complex reactions with examples of practical kinetic analysis. These recommendations are expected to provide a guidance for performing reliable and meaningful kinetic analysis in terms of practical usefulness and physico-chemical significance of the results.

Galukhin A., Vyazovkin S.

AbstractThis article reviews both time‐honored and most recent studies of the mechanisms and kinetics of cyanate esters polymerization. Different types of processes, including catalytic, non‐catalytic, bulk, solution, and nanoconfined ones are covered. The mechanistic and empirical models suitable for describing the kinetic and diffusion regimes of polymerization are discussed at length. Recent advances in methodology of the analysis of multistep polymerization reactions by means of model‐fitting and isoconversional techniques are considered as applied to cyanate esters. The importance of the calorimetric measurements in polymerization studies is emphasized.

Solomonov B.N., Yagofarov M.I.

• Compensation relationship is investigated in non-hydrogen-bonded systems. • Vaporization and solvation parameters obey the same compensation relationship. • Long-chain aliphatic compounds obey linear correlation with lower slope. • Vapor pressure at any temperature can be found from vaporization enthalpy. • Vapor pressure at any temperature and enthalpy can be found from boiling point. There is a well-known connection between the entropies (or Gibbs energies) and enthalpies of many processes, particularly solvation, called the compensation relationship. It has been recognized for a long time that hydrogen bonding in solvents has a significant effect on the compensation relationship. However, apart from that, little attention has been paid to the features of the correlation between the Gibbs energies and enthalpies of solvation that may manifest different classes of organic non-electrolytes. In this work we examined whether the Gibbs energies and enthalpies of solvation and vaporization of various non-hydrogen-bonded organic non-electrolytes obeyed the same relationship. It was established that, while most organic non-electrolytes, together with rare gases, follow the common linear correlation, long-chain aliphatics form the separate line with the lower slope. Root-mean-square deviation of the observed correlations was below 1 kJ·mol -1 , which enables to use them as a tool for predicting the Gibbs energies of solvation/vaporization from the enthalpies at 298.15 K and vice versa. Combined with our recent findings, this can be applied to determining the vapor pressure as a function of temperature from the vaporization enthalpy, or a single measurement of the vapor pressure at an arbitrary temperature, or the boiling point under a given pressure.

Galukhin A., Nosov R., Taimova G., Shulyatiev A., Nikolaev I., Islamov D., Vyazovkin S.

• Phenol-catalyzed cyclotrimerization of cyanate ester is studied • DSC, combustion calorimetry, and chromatography are employed • Kinetics is analyzed by isoconversional methodology • Important kinetic and mechanistic insights are obtained Differential scanning and combustion calorimetry in combination with isoconversional methodology and chromatography are applied to acquire kinetic and mechanistic insights into the reaction of phenol-catalyzed cyclotrimerization of cyanate ester. The only detectable reaction intermediate is found to be imidocarbonate, which is demonstrated to form in an irreversible manner. Isoconversional analysis indicates that the overall reaction kinetics at its early and late stages is respectively controlled by the irreversible formation of imidocarbonate ( E a ≈40 kJ mol −1 ) and a reaction of imidocarbonate with cyanate ester ( E a ≈70 kJ mol −1 ). Cyclotrimerization of neat imidocarbonate is analyzed as well. For this reaction, no intermediates are detected. Its overall kinetics is determined to occur as a single autocatalytic step. It is concluded that cyclotrimerization of imidocarbonate does not amount to any significant competition to the reaction between imidocarbonate and cyanate ester.

Notfullin A.A., Bolmatenkov D.N., Yagofarov M.I., Balakhontsev I.S., Ziganshin M.A., Solomonov B.N.

The compounds of the homologous series of n-alkyl benzoates (PhCOO-n-CnH2n+1) have a number of important applications. As for many low-volatile compounds, a few data on the vaporization thermodynamics of this class of compounds are available. Here we systemized and critically analyzed the available information on vapor pressures and vaporization enthalpies of short linear alkyl benzoates from methyl to pentyl and complemented these data by additional experimental investigation of long-chained compounds: the heat capacities and vapor pressures of pentadecyl, hexadecyl and heptadecyl benzoates were measured for the first time between 340 and 490 K using DSC and TG-FSC. Based on the experimental data and empirical approaches, we completely described the vaporization thermodynamics of a series of alkyl benzoates from methyl to eicosyl and established the correlation of some properties with the chain length. A way to predict the vaporization enthalpies and vapor pressures inside the homologous series in a wide temperature range was proposed and tested.

Vyazovkin S., Achilias D., Fernandez-Francos X., Galukhin A., Sbirrazzuoli N.

• Recommendations are provided for kinetic analysis of thermal polymerization. • Main focus is on analysis of DSC measurements. • Multi-step nature of polymerization kinetics is emphasized. • Model-fitting, isoconversional, and deconvolution analyses are discussed. • Specific advices are offered for efficient usage of each analysis. The present recommendations have been developed by the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC). The recommendations provide guidance on kinetic analysis of thermal polymerization, which incorporates both linear and crosslinking polymerization (curing). The focus is on treating the kinetics as measured by differential scanning calorimetry (DSC). The recommendations discuss basic reaction mechanisms and emphasize the multi-step nature of the polymerization kinetics. An overview of mechanistic and phenomenological models is provided for polymerization controlled by reaction kinetics and diffusion. Three different approaches to evaluation of kinetic parameters (activation energy, preexponential factor, reaction model) for individual steps are considered. These approaches comprise model-fitting, isoconversional, and deconvolution analyses. Practical advices are offered for effective usage of each approach. Attention is paid to the typical problems and to the ways of addressing them. The recommendations are intended to assist with efficiently conducting kinetic analysis and interpreting its results.

Sykam K., Donempudi S., Basak P.

Development of the non-halogenated flame retardants (FRs) is an emerging research area as halogenated FRs are prone to produce carcinogenic and persistent organic pollutants. In this context, 1,2,3-triazole synergized FR polymeric materials noticeably attained great interest in the last decade. The mini-review highlights the role of azide-alkyne click chemistry with specific reference to 1,2,3-triazole moiety covalently grafted FR for various polymeric systems. In particular, the intumescent FR mechanism of 1,2,3-triazole has been reviewed and the technical evidence for the mechanism is provided by fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) analysis. 1,2,3-triazole moiety is increasingly proving itself to be a potent non-halogenated FR and it has the potential to be adopted by the industry in near future.

Galukhin A., Nikolaev I., Nosov R., Vyazovkin S.

This study highlights the value of nonisothermal kinetic methods in selecting temperature conditions for the isothermal preparation of microporous polymeric materials. A dicyanate ester is synthesized and the kinetics of its polymerization in diphenyl sulfone are studied by calorimetry under nonisothermal conditions. The kinetics are analyzed by a model-based approach, using the Kamal model, as well as by a model-free approach, using an advanced isoconversional method. Both approaches correctly predict the time to completion of polymerization at a given temperature. The material prepared independently at the predicted temperature is characterized by electron microscopy and CO2 adsorption measurements and is confirmed to possess a microporous structure with a multimodal distribution of micropores with two major maxima at ~0.5 and 0.8 nm.