Thermal decomposition of the copolymer of polyethylene glycol fumarate with acrylic acid (p-EGF:AA) of two different compositions synthesized earlier was studied in the present work. TG and DTG curves prove that decomposition takes place in several stages. According to thermogravimetric curves it has been found out that for the copolymer with higher content of acrylic acid the decomposition of the copolymer’s sample is started at higher temperatures. It has been shown the shift of the temperature of decomposition’s start to the higher area with the increase of heating rate which is necessary for the detorsion of macromolecular coil. Experimental data processed using graphical methods of Kissinger–Akahira–Sunose and Friedman allowed us to calculate the activation energy of the thermal decomposition process. It has been established that the copolymer with the composition of 21.03:78.97 mass.% has lower meaning of activation energy than the one with the composition of 68.96:31.04 mass.%. As a result of calculation one can see that the meanings found out using these methods depend slightly on conversion. Using Achar-Brindley-Sharp method and the method of invariant kinetic parameters the kinetic triplet of the decomposition process has been found which was used to build the calculated curve. The dependences of g(α) on α using these parameters showed a satisfactory agreement of calculated curves with the experimental ones. One can conclude that the decomposition process of the copolymer of polyethylene glycol fumarate with acrylic acid is well described with of D3 (three-dimensional diffusion) model.

The study of the kinetic parameters of copolymers based on polyethylene glycol fumarates, as well as the external and internal effects on them, is essential for production processes at various levels. This will solve a whole range of issues in the field of the shelf life of materials and storage conditions. All these point to the relevance of this research. The authors of the research attempt to test the most common thermogravimetric data processing methods and to improve them in terms of the quality of the predictive capabilities of the resulting regression equation. Both of them are important for the production of initial components and the manufacture of the final product from the studied materials. Therefore, the study and further use of the numerical data of the TG/DTA curves applies to both theoretical and practical branches of science. Thus, summarizing the experimental data on the thermal stability studies, we assume that p-EGF: AA copolymers with compositions of 21.03:78.97 and 68.96:31.04 wt.% have a relatively high degree of resistance to heating. It was found that the calculation by the FR method agreed well with the results of the KAS method. It should be noted that for the p-EGF: AA copolymer (21.03:78.97 wt.%) at heating rates of 5.0, 10.0, 20.0 °С∙min–1, the average activation energy data obtained for two methods increase in the following series:KAS E = 187.34 kJ /mol

Thermal performance of copolymer based on polyethylene glycol fumarate and methacrylic acid in a dynamic mode, in an inert nitrogen environment are considered in the present work. Kinetic evaluation of thermal decomposition process was conducted using three different data processing methods (Friedman, Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose). Utilizing a mixed-method approach kinetic triplets Eа, A, g(a) were received. The received kinetic parameters were used to calculate the thermodynamic characteristics of Gibbs energy (∆G), enthalpy (∆H) and entropy of activation (∆S). Copolymer thermal gravimetric analysis (TGA) and differential thermogravimetric analysis (DTA) curves were studied under nitrogen environment using a heating rate of 2,5, 5, 10 or 20°C/min. The method of Invariant Kinetic Parameters was used to identify the reaction model and pre-exponential factor. The main phase of copolymer decomposition was set, which occurred within a narrow temperature interval and is evidenced by the spike on the differential curve. Values for 13 reaction models were received. Utilised methods resulted in a proper energy activation alignment within 223-229 kJ mol-1. Design and experimental data provided close values. TGA and DTA curve analysis has shown a sufficient thermal stability of these copolymers under the nitrogen environment.

The thermal decomposition of polyethylene glycol fumarate–acrylic acid copolymer is investigated at different rates of heating. It is shown that increasing the rate of heating raises the temperature of the onset of decomposition. The kinetic parameters of decomposition are calculated using the integral Kissinger–Akahira–Sunose procedure. It is found that at different degrees of conversion, the activation energies are very close: E = 205–227 kJ/mol. The effect the composition of the copolymer has on the results from kinetic calculations is shown. The Coates–Redfern approach is used to determine the pre-exponential factor and the model of thermal decomposition. Calculated thermogravimetric curves are constructed and compared to experimental ones.

Metal-polymer composites based on copolymers of polypropylene glycol maleate phthalate with acrylic acid and metallic nickel and silver were synthesized for the first time. The objects obtained were characterized by infrared (IR) and Raman spectroscopies, thermogravimetry, a scanning electron microscope with energy dispersive spectroscopy, and atomic emission spectrometry. The catalytic activity of new metal-polymer composites that exhibited a rather high efficiency in the reactions of electrocatalytic hydrogenation of pyridine was studied. It is shown that nanoparticles of metals are evenly distributed in the volume of the polymer matrix; more than 80% of nanoparticles are in the range from 25 to 40 nm and have spherical and rhombic shapes. The reusability of the obtained composites is shown.

In the article the thermal characteristics of a copolymer of poly(ethylene glycol)fumarate with methacrylic acid were studied in a dynamic mode in a nitrogen atmosphere for the first time. A kinetic analysis of the thermal destruction process was carried out using three different data processing methods (Freeman-Carroll, Sharp-Wentworth, Achar). Thermodynamic characteristics were also calculated, namely the change in the Gibbs energy (∆G), enthalpy (∆H) and entropy of activation (∆S). The curves of thermogravimetric and differential thermogravimetric analysis of the copolymer were studied in a nitrogen atmosphere at a heating rate of 10 °C/min. The main stage of the copolymer decomposition was found to occur in a narrow temperature range, which is confirmed by a peak in the differential curve. Changes in the reaction rate of the copolymer were shown due to the decrease in the sample mass. It was shown that the results of kinetic analysis depend on the molecular structure of the compounds under study. The activation energies found by the Freeman-Carroll method have lower values, while the Achar and Sharp-Wentworth methods give the same results.

In this work, the thermal decomposition of copolymers based on polyethylene glycol fumarate with the acrylic acid using various ratios of initial monomers has been studied for the first time. The samples were studied in air and nitrogen. According to the thermograms analysis, it was found that the copolymer sample decomposition begins at higher temperatures for a copolymer with high content of polyester resin. The copolymer is vigorously oxidized by the oxygen when heated in air, and one can observe almost complete sample decomposition, whereas it decomposes with a residue of ~ 15% in an inert medium. The activation energies for copolymers with different compositions were estimated using the differential methods of Freeman-Carroll, Achar and Sharpe-Wentworth. The activation energy values found by the three methods demonstrated a good convergence. It was shown that, the activation energy values are higher (~ 200 kJ/mol in the inert medium, and ~ 95 kJ/mol in the oxygen atmosphere) for a copolymer with a lower composition of polyester resin, and the activation energy is ~180 and ~85 kJ/mol for a copolymer with a greater composition of p-EGF-AA. The copolymer is more thermostable in the nitrogen atmosphere according to the kinetic parameters. Additionally, there were determined the thermodynamic characteristics, such as the Gibbs energy (∆G) and the entropy (∆S). They also confirm the destruction process dependence on the components ratio in the synthesized copolymer.

New mono- and bimetallic polymer nanocomposites based on polyethylene( propylene) glycol maleates with acrylic acid and silver and nickel metals were prepared and studied. Metal particles were immobilized into copolymer supports by reduction of Ag+ and Ni2+ ions from solution of their nitrates to Ag-0 and Ni-0 in the presence of a catalyst, a solution of silver chloride in aqueous ammonia. The structure and composition of the complexes were determined by spectroscopy, calorimetry, microscopy, and chromatography. The catalytic activity was studied using pyridine hydrogenation as a model reaction.

Comparative analysis of the physicochemical properties of styrene solutions of poly(propylene glycol maleate phthalate) with different initial reactant ratio was performed. Increased content of phthalic anhydride in the initial monomer mixture in the synthesis of the unsaturated polyester leads to worse properties of the ready product, poly(propylene glycol maleate phthalate)–styrene copolymer prepared by cold curing. Solutions of poly(propylene glycol maleate phthalate) in styrene with ~30 wt % styrene content exhibit the highest viscosity, allowing the use of the cured product as a structural composite material. The solutions containing ~40 wt % styrene have lower viscosity and are suitable for preparing less hard plastics for general purposes.

The possibility of preparing new polyampholyte polymers based on polypropylene glycol fumarate–acrylic acid–dimethylaminoethyl methacrylate terpolymers was demonstrated. The main relationships of radical terpolymerization in dioxane, including binary systems participating in the terpolymerization, were studied. The block lengths, transition probabilities, and Harwood block structure parameter were calculated for the terpolymers from the copolymerization constants for the binary systems. These parameters reflect the arrangement of the macroradicals in the chain. The morphology of the polymer surface was studied by scanning electron microscopy, and the surface pore size was estimated. The influence of organic solvents and pH on the sample swelling was studied, and the isoelectric point (pH 6.00) of the terpolymer was determined.

It is shown that copolymers of polyethylene- and polypropyleneglycolmaleates (p-EGM and p‑PGM) with acrylic acid (AA) can be used as matrices for the preparation of effective metal-polymer complexes for hydrogenation of organic compounds. Electron microscope and dynamic scattering are used to determine the average nanoparticle size of 112 nm; the nanoparticles are spheres with a uniform distribution along the polymer’s cross section. The contents of nickel and cobalt in p-EGM/AA are 0.52 and 0.48 wt %, respectively, and 0.49 and 0.51 wt % in p-PGM/AA, respectively. It is found that raising the temperature from 25 to 40°C allows the rate of pyridine hydrogenation to be increased substantially as a result of catalyst activation and an increase in the number of catalyst active centers, due to the swelling of the polymer network and its transition from the tight globular to the expanded state. Raising the current’s strength from 1 to 3 A lowers the yield of piperidine, which does not allow the increase in the current density to be used to shorten the length of synthesis. It may be concluded that the experimental data allow a final product of hydrogenation with higher rates and yields to be obtained.

Results of the influence of external factors on process of immobilization of metal nanoparticles on copolymers based on unsaturated polyester resins with unsaturated carboxylic acids were considered in the article. The effects of concentration of cobalt chloride solutions and distribution of metal particles by sizes in the matrix were studied. Results showed that increasing of cobalt concentration in solution shifts the equilibrium towards the formation of larger particles, i.e. there is a tendency to flocculation and formation of bi-and polymodal dispersions. The dependence of the dispersion formed at reduction of metal containing particles on the reducing agent and its concentration were researched. Potassium hypophosphite and sodium tetrahydroborate were used as reducing agents. It was found that upon reduction by sodium tetrahydroborate of cobalt nanoparticles have larger sizes than by using potassium hypophosphite.

The structure and composition of the hydrogels on the basis on unsaturated polyester resins with unsaturated carboxylic acids have been studied by scanning electron microscope. It was proved that their porous structure and their use as a matrix for immobilization of the metal particles. The results of the influence of external factors such as temperature, pH and the nature of the solvent on the new metal-polymer complexes on the basis of polyethylene (propylene) glycol maleate are shown in the article. The experimental data showed that the effect of temperature on the degree of swelling of the polymer-metal complexes are insignificant. These complexes exhibit a high degree of swelling in alkaline medium, and with increasing solvent polarity increase the degree of swelling is observed. High indexes of swelling ability of metal-polymeric complex in an alkaline medium have a positive impact on the results of the electrocatalytic hydrogenation, as with increasing swelling ability of MPC availability of substrate molecular to catalyst increases. There is a definite correlation between the dielectric constant and the degree of polymers swelling, in particular during the transition from solvents with an average polarity to pyridine. However, there is not such a significant reduction in the swelling degree.

The radical copolymerization of poly(ethylene glycol maleate) with acrylamide was performed for the first time to obtain 3D cross-linked polymers. The influence of temperature, pH of the medium, and organic solvents on the behavior of the synthesized copolymers was studied. The possibility of obtaining nickel nanoparticles in the bulk of the polymer gel for pyridine hydrogenation was demonstrated.

По разработанному методу расчета вычислены стандартные энтальпии образования манганито-ферритов состава LnMIIMnFeO5.5 (Ln – редкоземельный элемент, MII – щелочно-земельный металл). Методом ионных инкрементов рассчитаны их стандартные энтропии и по уравнению Гиббса–Гельмгольца – их стандартные энергии Гиббса образования.

LaM 3 I CrMnO6 (MI = Li, Na) and LaM 3 II CrMnO7.5 (MII = Mg, Ca) chromitomanganites were synthesized by ceramic technology from lanthanum oxide, chromium(III) oxide, manganese(III) oxide, lithium carbonate, sodium carbonate, magnesium carbonate, and calcium carbonate. X-ray powder diffraction shows that these compounds crystallize in cubic or tetragonal systems with the following unit cell parameters: for LaLi3CrMnO6 (cubic): a = 10.98 Å, V ○ = 1323.75 Å3, Z = 8, V u.c ○ = 165.47Å3, ρX = 3.64, ρpycn= 3.60 ± 0.04 g/cm3; for LaNa3CrMnO6 (tetragonal): a = 10.96 Å, c = 15.73 Å, V ○ = 1889.51 Å3, Z = 16, V u.c ○ = 118.09 Å3, ρX = 5.77 g/cm3, ρpycn = 5.70 ± 0.07 g/cm3; LaMg3CrMnO7.5 (cubic), a = 10.98 Å, V ○ = 1322.31 Å3, Z = 8, V u.c ○ = 165.29 Å3, ρX = 4.41 g/cm3, ρpycn = 4.35 ± 0.07 g/cm3; and for LaCa3CrMnO7.5 (cubic): a = 10.97 Å, V ○ = 1319.78 Å3, Z = 8, V u.c pO = 164.97 Å3, ρX = 4.89 g/cm3, ρpycn = 4.85 ± 0.05 g/cm3.

Manganite ferrites NdM 1.5 II MnFeO 6 (M II = Mg, Ca, Sr, Ba) were synthesized from neodymium(III), manganese(III), and iron(III) oxides and alkaline-earth metal carbonates by a ceramic technology. By grinding the obtained compounds in a ball mill, their nanostructured particles were produced, the sizes of which were determined with an electron microscope. X-ray diffraction study established that the nanostructured compounds crystallize in the cubic and tetragonal systems with the following lattice parameters: NdMg 1.5 MnFeO 6 (tetragonal): a = 10.955 Å, c = 17.848 Å, V 0 = 2141.975 Å 3 , Z = 16, V e1.cel1 0 = 133.873 Å 3 , ρ X-ray = 4.80 g/cm 3 , and ρ pycn = 4.76 ± 0.05 g/cm 3 ; NdCa 1.5 MnFeO 6 (cubic): a = 10.809 Å, V 0 = 1262.864 Å 3 , Z = 8, V e1.cel1 0 = 157.858 Å 3 , ρ X-ray = 4.32 g/cm 3 , and ρ pycn = 4.27 ± 0.03 g/cm 3 ; NdSr 1.5 MnFeO 6 (cubic): a = 10.911 Å, V 0 = 1298.953 Å 3 , Z = 8, V e1.cel1 0 = 162.369 Å 3 , ρ X-ray = 4.93 g/cm 3 , and ρ pycn = 4.88 ± 0.05 g/cm 3 ; and NdBa 1.5 MnFeO 6 (tetragonal): a = 11.011 Å, c = 18.001 Å, V 0 = 2182.479 Å 3 , Z = 16, V e1.cel1 0 = 136.405 Å 3 , ρ X-ray = 6.78 g/cm 3 , and ρ pycn = 6.75 ± 0.07 g/cm 3 .

Manganite ferrites NdM I MnFeO 5 (M I = Li, Na, K) were synthesized from neodymium(III), manganese(III), and iron(III) oxides and lithium, sodium, and potassium carbonates by a ceramic technology. By grinding the obtained compounds in a ball mill, their nanostructured particles were produced, the sizes of which were determined with an electron microscope. X-ray powder diffraction study and indexing established that the nanostructured compounds NdM I MnFeO 5 (M I = Li, Na, K) crystallize in the cubic system with the following lattice parameters: NdLiMnFeO 5 : a = 20.100 ± 0.034 Å, V 0 = 8120.60 Å 3 , Z = 10, V un.cell 0 = 812.06 Å 3 , ρ X-ray = 7.14 g/cm 3 , and ρ pycn = 7.09 ± 0.06 g/cm 3 ; NdNaMnFeO 5 : a = 20.102 ± 0.032 Å, V 0 = 8123.03 Å 3 , Z = 10, V un.cell 0 = 812.30 Å 3 , ρ X-ray = 7.11 g/cm 3 , and ρ pycn = 7.04 ± 0.06 g/cm 3 ; and NdKMnFeO 5 : a = 20.107 ± 0.011 Å, V 0 = 8129.09 Å 3 , Z = 10, V un.cell 0 = 812.91 Å 3 , ρ X-ray = 7.03 g/cm 3 , and ρ pycn = 6.95 ± 0.07 g/cm 3 .