Synthesis of an inorganic-organic polymer blend from orthoboric acid and caprolactam

The possibility of modifying boron polyoxide with an oligomeric amide upon thermal dehydration of orthoboric acid and oligomerization of caprolactam in a common melt is shown. The products obtained after thermal pretreatment of the initial blend containing 30 wt % caprolactam are investigated. It is shown that the main processes at T < 200°C are dehydration of orthoboric acid and hydrolysis of caprolactam with the formation of ε-aminocaproic acid. At temperatures of 225–260°C, the predominant process is the formation of boron polyoxide and a caprolactam-based oligomeric product. The data of ¹¹B NMR spectroscopy show that the chemical transformations of caprolactam occur against the background of the N:B donor-acceptor interaction. The two-dimensional [¹¹B-¹H] heteronuclear correlation spectrum indicates that the systems obtained upon thermal treatment are solid solutions.     

Modeling of the localy-functional properties of the material damaged by fields of defects

It is shown that for Mindlin media with fields of defects there is an alternative interpretation allowing to describe the material affected by defects as equivalent functionally-gradient material with varying properties for coordinates, modeled in the classical theory of elasticity. We establish clear relationships for determining the properties of functionally graded materials by the solutions, taking into account the availability of fields of defects. It is shown that, in general, the properties of equivalent functionally-gradient material depend on the coordinates, as well as on the loading and boundary conditions.     

Macrokinetics of carbonaceous feedstock pyrolysis in a tubular reactor of variable cross section

A macrokinetic model of carbonaceous feedstock pyrolysis in a tubular reactor of variable cross section was constructed. It was shown that, to intensify the pyrolysis in such a tubular reactor, its diameter should vary depending on the viscosity of the reaction products.     

Decoration of Carbon Nanotubes with MnO2 Nanoparticles Under Potassium Permanganate Treatment

Russian Physics Journal -     

Plasma oscillations in fullerene molecules within the random phase approximation

A method is presented for calculating the density of plasma excitation modes in fullerene molecules, which makes it possible to describe more accurately the specific features of the spectra as compared to the models proposed previously. The method is based on the inclusion of the total contribution of π and σ electrons to the spectra of collective oscillations in the molecules. This allows one to consider fullerene molecules with an arbitrary symmetry and arbitrary substituents. A comparative analysis of the experimental curves obtained for resonance electron capture and the results of numerical simulations for C₆₀, C₇₀, and C₇₆ molecules has demonstrated that not only the main maxima but also the ranges of the formation of negative ions coincide.     

Calculation of the thermodynamic properties of the dimethacrylate esters of aliphatic glycols

Russian Chemical Bulletin -