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The factors affecting the methanolysis of polycarbonates catalyzed by sodium methylate are studied. The conversion rate increases with an increase in the basic properties of solvents; the rate of methanolysis depending on the amount of solvent (tetrahydrofuran) is described by an extreme dependence. Changes in sodium methylate concentration and temperature have a small effect on the methanolysis of polycarbonates.

Theoretical study of the reactions of urea with methanol with the formation of O-methyl carbamate and reactions of O-methyl carbamate with methanol with the formation of dimethyl carbonate by the B3LYP and M06 methods has shown that these transformations can proceed according to the concert mechanism. Reactions involving methanol monomers cannot be real pathways for the formation of reaction products. In both transformations, reactions involving linear methanol dimers and trimers are kinetically and thermodynamically more preferable than reactions with methanol monomers. The stage that determines the rate of formation of dimethyl carbonate is the interaction of O-methyl carbamate with methanol associates. The interactions of urea with methanol associates with the formation of O-methylcarbamate are almost irreversible. However, the reactions of O-methylcarbamate with methanol associates with the formation of dimethyl carbonate are substantially reversible. This requires the use of measures to shift the equilibrium towards the reaction products in this interaction.

The mechanism of N-methylformamide metathesis with dimethyl carbonate, which leads to the formation of N,O-dimethyl carbamate, is studied using the quantum-chemical B3LYP/6-311++G(df,p) approach. The reaction consists of three stages: the conversion of formamide to iminol; the adding of dimethyl carbonate at the azomethine bond of iminol; and decomposition of the resulting product into carbamate and methyl formate. The second stage limits the rate of interaction. All stages proceed through concerted cyclic transition state, and all of them are catalyzed efficiently by a monomer and a dimer of methanol.

The mechanisms of noncatalytic and autocatalytic addition–elimination reactions of dimethyl carbonate with methylamine have been studied in terms of wB97XD/6-311++G(df,p), M06/6-311++G(df,p), and PBE0/6-311++G(df,p) quantum chemical methods, and thermodynamic and activation parameters of these reactions have been calculated. The rate-determining stage is the formation of tetrahedral carbon intermediate. The addition–elimination mechanism is preferred over the autocatalytic SN2 mechanism determined by enhanced donor–acceptor and acid–base properties of amine complexes with alcohol associates in comparison to amines.

The B3LYP/6-311++G(df,p) quantum-chemical simulation has revealed that linear associates of methanol catalyze the ketone–enol, nitro–aci-nitro, and carbamate–azomethinenol tautomeric transformations. All the reactions proceed via the coherent transition states. The catalytic effect is enhanced with the increased alcohol degree of association. The acid-base properties of methanol are changed similarly.

The mechanism of transformation of 2-hydroxyethyl carbamate into ethylene carbonate was studied at the DFT B3LYP and M06 levels of theory. The reactions proceed through pre- and post-reaction complexes and cyclic transition states. The free energy barrier decreases when ethylene glycol molecule or zinc oxide is involved.

Quantum chemical study of the reaction of ethylene carbonate with methanol associates at the B3LYP/6-311++G(df,p) level of theory revealed two probable mechanisms. The one-step mechanism involves SN2 substitution at the sp2-hybridized carbonyl carbon atom, while the two-step mechanism implies nucleophilic addition to the carbonyl group with formation of tetrahedral intermediate and subsequent elimination. All the examined reactions go through asymmetric concerted transition states.

Thermodynamic parameters of the reactions of dimethyl carbonate cis-cis and cis-trans conformers with methylamine, methylamine dimer, and methylamine complexes involving linear methanol associates have been computed with the B3LYP and WB97XD quantum-chemical methods. The both methods have given similar results. Thermodynamically, reactions of the cis-trans conformer are preferred over the analogous reactions of the cis-cis conformer, and the reactions with methylamine dimer and methylamine-methanol trimer complex are preferred over the reactions with methylamine monomer. The acid-base properties of the hydrogen-bonded methanol complexes are significantly enhanced with increasing degree of association. Stability of the methylamine complexes with methanol clusters is increased with more of the alcohol molecules involved.

Quantum-chemical method B3LYP/6-311++G(df,p) was applied to the study of complex formation between phenol and methanol. The complexes of molecules bound by the hydrogen bond possess enhanced donoracceptor and acid-base properties as compared to monomer molecules. The reactions of phenol and methanol complexes with methyl isocyanate proceed through a concerted late asymmetric transition state by the type of nucleophilic addition. The most kinetically and thermodynamically favorable transformation is the process involving the complex “phenol-acceptor, methanol-donor.” Phenol compounds are able to catalyze the addition of alcohols to isocyanates.

The reaction of isocyanic acid with ethylene glycol associates was studied by the B3LYP/6–311++G(df,p) quantum chemical method. The reaction mechanism includes formation of pre- and post-reaction complexes and cyclic asymmetric late transition states. The energy barrier decreases with increase in the degree of association of ethylene glycol.

Thermodynamic parameters of the major and side reactions in the course of dimethyl carbonate formation from ethylene carbonate and methanol have been determined by means of the B3LYP/6-311++G(df,p) quantum-chemical method. Enthalpy and entropy of the reactions have increased with enhanced association of the alcohols. Temperature dependences of the equilibrium constants have been determined. Technological conditions of dimethyl carbonate production via ethylene carbonate methanolysis have been elaborated.

The mechanisms of the reactions of methyl isocyanate with phenol monomer and linear dimer were studied at the B3LYP/6-311++G(df,p) level of theory, and the results were compared with those obtained for the reactions with methanol associates. All the examined reactions involve asymmetric concerted transition states. The addition of phenol is electrophilic, whereas the addition of methanol is nucleophilic. The formation of H-complexes with phenol and methanol molecules increases not only electron-donating power but also gasphase acidity and basicity.

Catalytic activity of manganese and copper oxides in the oxidation of sulfur compounds, including sodium sulfide, sodium hydrosulfide and ammonium sulfide was studied. Polymeric catalyst based on copper(II) and manganese(IV) oxides showed high activity, especially in the oxidation of sodium hydrosulfide and ammonium sulfide. Kinetic investigation showed that all the reactions are first order with respect to oxygen concentration and zero—to the source concentration of sulfur compounds.

The effect of nonspecific solvation on the reactivity of methyl isocyanate toward linear methanol associates and thermodynamic parameters of this reaction was studied at the B3LYP/6-311++G(df,p) level of theory in terms of the polarizable continuum model (PCM). Transformations in the liquid phase are more exothermic than in the gas phase. Change of the solvent nature leads to variation of the geometric parameters and intrinsic free energies of the reactants and transition states. Increase in solvent polarity is accompanied by increase in the degree of asymmetry and polarity of transition states. As the dielectric permittivity rises, the polar constituent of the Gibbs energy of solvation decreases, while its nonpolar constituent increases. Owing to the opposite variations of these constituents of the Gibbs energy of activation, the reaction is weakly sensitive to solvent polarity.

Thermal decomposition of urea in ethylene glycol with formation of isocyanic acid and ammonia was studied at the B3LYP/6-311++G(df,p) level of theory. The decomposition process is efficiently catalyzed by monomeric and dimeric forms of ethylene glycol. Ethylene glycol dimer formed via intermolecular hydrogen bonding is a stronger acid than the monomeric species, which is responsible for the higher catalytic activity of the former. Ethylene glycol associates efficiently catalyze addition of ammonium to isocyanic acid in the synthesis of ethylene carbonate.

Piperidine N-carboxamides were shown to activate the anionic polymerization of ɛ-caprolactam. The activator structure affects properties of the resulting polycaproamide.

The kinetics of polymerization of vinyl acetate in individual and mixed solvents was studied. The reaction rate constant and the rate of chain transfer in the mixed solvent were calculated, molecular weights and some adhesive characteristics of poly(vinyl acetate) obtained by the radical polymerization in solution were determined. A comparative analysis of the polymers obtained in the individual and mixed solvents was performed. It is shown that the change in the solvent composition can affect the rate of reaction and the poly-(vinyl acetate) adhesive properties.

By B3LYP/6-311++G(df,p) quantum-chemical method complete thermodynamic characteristics (enthalpies, entropies, total Gibbs energies, equilibrium constants) were evaluated for separate stages of the thermal decomposition of dimethyl toluylene-2,4- and dimethyl toluylene-2,6-dicarbamates with the formation of 2,4- and 2,6-diisocyanates and methanol. The temperature ranges providing the equilibrium yield of 2,4- and 2,6-toluylene diisocyanates equal to 95–99% were estimated. Principal possibility of obtaining practically pure 2,4- and 2,6-toluylene diisocyanates while decomposing the mixture of dimethyl toluylene-2,4- and -2,6-dicarbamates due to the regulation of temperature of the process was shown.

It was shown by quantum-chemical method B3LYP/6-311++G(df,p) that in the autocatalytic reaction the molecules of methyl carbamate formed prereaction complexes with the monomer and dimer of methanol. The complexes possess higher electron-donor properties than free alcohol molecules thus increasing the activity of complexes in the reaction with isocyanates. The products of the autocatalytic reaction are new molecules of carbamate and azomethinenol. The conversions occur through concerted asymmetric late transition states. The isomerization of azomethinenols into carbamates is catalyzed by molecules of alcohols and their associates. The autocatalytic reaction of isocyanates with alcohols becomes possible owing to the ability of alcohols to catalyze the mentioned isomerization.

The mechanism of addition of linear methanol associates (monomer, dimer, trimer) to aryl isocyanates at their C=N and C=O bonds was investigated applying the quantum-chemical method B3LYP/6-311++G(df,p). Notwithstanding the electronic character of substituents in the aromatic ring of the isocyanates all reactions proceed through concerted asymmetric late transition states. The addition to the C=N bond is considerably more preferable than to the C=O bond. In the transformations under consideration the intermolecular donor-acceptor interactions between the reagents result in the appearance of abnormal selectivity.

Using methods of nuclear magnetic resonance, gel-permeation chromatography, and differential-scanning calorimetry, we showed that N-carboxamides were capable of polymerization. The polymerization mechanism of N-carboxamides in the presence of ɛ-caprolactam sodium salt was suggested.

Addition of linear methanol associates at the C=N and C=O bonds of methyl isocyanate was studied in terms of the B3LYP/6-311++G(df,p) hybrid quantum-chemical method. The addition at the C=N bond is more favorable than the reaction at the carbonyl group. All reactions involve late asymmetric cyclic transition states. The activity of the reacting system increases in parallel with the degree of methanol association. Isomerization of methyl hydrogen methylcarbonimidate into carbamate is catalyzed by methanol associates. Thermal decomposition of carbamates with formation of isocyanates can occur in autocatalytic mode.

The interaction of isothiocyanates with amino acids may proceed to yield both low-molecular-mass products and polymer compounds. The structure of these compounds depends on the nature of isothiocyanate, and amino acid is strongly affected by the basicity of the medium.

The thermodynamic parameters of reactions of phenyl isocyanate with methanol monomer, dimer, and trimer were calculated by the B3LYP and MP2 quantum-chemical methods. The enthalpies and entropies of transformations were found to increase as the degree of methanol association grew. An isokinetic dependence was observed for the transformations under consideration. The influence of the polarity of solvents on the Gibbs energies of these reactions was estimated.

The effect of the nature of curing agents on the properties of sealants based on polyetherurethanethiols was examined.

Reaction of dicarboxylic acid with benzyl alcohol under the microwave irradiation proceeds faster as compared to the thermal conditions. The main reaction products are alkyl dicarboxylates, and the monoester and dibenzyl ether are formed as the side products. A proposal about the nature of the nonthermal effect in the reactions stimulated by the microwave irradiation is considered.

Quantum-chemical calculations at the B3LYP/6-311++G(df,p) level of theory showed that reactions of phenyl isocyanate with methanol associates involve formation of pre-and post-reaction complexes. The reactions proceed through late asymmetric cyclic transition states. The height of the energy barrier decreases as the degree of association of the alcohol increases. The relative change in the Gibbs energy in the reaction of phenyl isocyanate with methanol also becomes smaller as the degree of alcohol association increases.

Thermodynamic parameters of reactions of methyl and phenyl isocyanates with a series of compounds were determined by quantum-chemical calculations. The products of these reactions model for various functional groups present in commercial polyurethanes. The thermodynamic stability series for compounds formed from aliphatic and aromatic isocyanates were constructed.

Sulfur-containing oligoethers were prepared by polycondensation of thiodiglycol in the presence of acid catalysts. These oligoethers are oligomers with terminal hydroxy groups, comprised of oxyalkyl sulfide units.

The performance of new polyfunctional additives containing bis(2,6-di-tert-butyl-4-hydroxyphenyl) polysulfide and dicyclopentadiene-sulfur copolymer was studied with respect to SKI-3 and vulcanizates thereof. These additives act not only as stabilizers but also as vulcanizing agents improving a number of physicomechanical characteristics of the vulcanizates.

The composition of oligoethers that are components of Laprol-373 and of products of their reaction with 2,4-toluylene diisocyanate were studied by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF).

The thermal decomposition of oligomeric α-alkoxyhydroperoxides (I) is described by a first-order rate law and characterized by an activation energy equal to 19.7 kJ/mol. A chain mechanism and a rate law for this reaction are proposed. The effect of amine and phenolic stabilizers on decomposition is studied, the efficiency of phenolic stabilizers is examined, and the effective rate constant of the acid-catalyzed decomposition of compounds I is determined.

Ozonolysis in hexane of ternary ethylene-propylene rubber (SKEPT), accompanied by formation of oxygen-containing groups and intermolecular cross-linking, was studied. These processes become more pronounced when ozonolysis is performed in hexane containing pyridine.

Reaction of 3,4-epoxy-1-butene with dichlorocarbene is accompanied by deoxygenation and yields a mixture of 1,1-dichloro-2-vinylcyclopropane, 2,2,2',2'-tetrachlorobicyclopropyl, and 2,2-dichlorocyclopropyloxirane. Arenesulfenyl chlorides react with 3,4-epoxy-1-butene to afford both Markownikoff and anti-Markownikoff addition products, whereas vinylethylene carbonate gives rise exclusively to the anti-Markownikoff adducts.

A process was developed for production of dicyclopentadiene from the C5 fraction of hydrocarbon pyrolysis. Conditions were found ensuring production of high-purity dicyclopentadiene.

Polymer–bitumen binders for the highway engineering were obtained by the addition of a ternary ethylene–propylene rubber to a bitumen. The addition of a vulcanizing agent to a polymer–bitumen composition caused the structuring of the system through cross-linking of rubber molecules in the bitumen matrix that was confirmed by the study of structural viscosity of the polymer–bitumen compositions, as well as molecular mobility by the methods of NMR-relaxation and pulsed field gradient NMR-relaxation (self-diffusion).

Reaction of 3,4-epoxy-1-butene with dichlorocarbene is accompanied by deoxygenation and yields a mixture of 1,1-dichloro-2-vinylcyclopropane, 2,2,2',2'-tetrachlorobicyclopropyl, and 2,2-dichlorocyclopropyloxirane. Arenesulfenyl chlorides react with 3,4-epoxy-1-butene to afford both Markownikoff and anti-Markownikoff addition products, whereas vinylethylene carbonate gives rise exclusively to the anti-Markownikoff adducts.

The influence of donor–acceptor interactions and localisation energies on the reactivity of addends in the 1,3-dipolar cycloaddition reaction is examined. It is shown that the interactions between the symmetric frontier orbitals and between the antisymmetric frontier orbitals are qualitatively different in (4π+2π)-cycloaddition reactions. The effects arising as a result of the interaction of the symmetric frontier orbitals lead to an alteration of the position of the transition state on the potential energy surface for the reaction and increase the sensitivity of the 1,3-dipolar cycloaddition reactions to localisation effects. The bibliography includes 113 references.