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Vol 8, No 1 (2013)
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SYNTHESIS AND PROCESSING OF POLYMERS AND POLYMERIC COMPOSITES

3-14 68
Abstract
In this article both types of Pickering emulsions – oil/water and water/oil – and their applications in the synthesis of different polymers have been considered. Pickering emulsions are dispersions stabilized by solid particles adsorbed at oil-water interface instead of conventional emulsifier. The influence of various solid particles, their amount and interaction on emulsions formation, stability and morphology with various suspended solid particles have been considered. Phase inversion phenomena and factors (such as wettability of solid particles) affecting them have been described. The interest to Pickering emulsions for the last decade is highly fueled by eco-friendly and cost-effective manufacture of hybrid polymer particles and nanocomposites with supracolloidal structures. The Pickering emulsion polymerization or suspension polymerization allows preparing in situ reinforced nanostructural polymer composites, unusual latexes and microcapsules with unique properties.
15-19 50
Abstract
Works on calculation and application of statistical moments used to interpret the random distribution functions and to characterize the whole curve shape were performed for analyzing the rheometric curves of rubber blends curing. By applying correlation analysis a high level of relation closeness between vulcanization parameters and quantitative curve characteristics (amplitude and mode) as well as statistical moments (mathematical expectation, dispersion, asymmetry coefficient and excess coefficient) was established. Methods of multiple correlation were used for the approbation of forecasting of curing characteristics of elastomeric materials based on the calculated statistical moments for a large data array was carried out.
20-23 43
Abstract
Composites based on LDPЕ, HDPЕ and oil-extended EPDM were investigated. It is shown that the matrix polymer predetermines the depth of completion of phase segregation and the structure of dynamic thermoplastics formed by reactionary blending during dynamic vulcanization of the thermoplastic-rubber blend
24-35 32
Abstract
The time dependence of the mechanical losses of low density polyethylene (LDPE) filled with fine particles of shungite in the process of periodic dynamic loading at changing frequency of loading and temperature was studied. It was shown that upon increasing the filler concentration and loading frequency these dependences are either similar in nature or shifted in the time-temperature scale on the graphs. The temperature and time dependent parameters and the interpretation of their physical meaning were proposed. It was confirmed that development of relaxation processes occurs in filled polymers under dynamic loading. A relationship between the parameters of these processes is described by logarithmic and exponential functions. These dependencies are determined by both the polymer matrix and the transition polymeric layer formed on the filler surface.

THEORETICAL BASES OF CHEMICAL TECHNOLOGY

36-42 81
Abstract
Different variants of calculation sets of the distillation column with infinite separation ability are investigated. With a ternary zeotropic mixture as an example the number of calculation sets is determined. Examples of rating and design calculation are given.
43-50 63
Abstract
The concentration dependences of integral vaporization heats of binary mixtures were calculated for atmospheric pressure with the use of experimental data. The character of changes of these dependencies under the influence of varying temperature was analyzed.
51-55 33
Abstract
The article shows the possibility of using formal analogy of processes with restructuring of the original system to calculate the main parameters of self-dispersion: interfacial tension at the interface and the drops radius of the formed emulsion.
56-61 37
Abstract
The search and analysis of the ground state, intermediate and transition states of carborane(12) thermal isomerization was performed by means of quantum-chemistry methods using B3LYP/6-311+G(d,p) and M062X/6-311+G(d,p) functionals. The framework rearrangement mechanisms such as the triangular face rotation, the pentagonal pyramid rotation, as well as mechanisms via cubeoctahedral and anticubeoctahedral transition states were studied.

CHEMISTRY AND TECHNOLOGY OF ORGANIC SUBSTANCES

62-65 48
Abstract
The kinetics of oxidation of 2,4,6-trimethylaniline hydrochloride with ammonia peroxydisulfate in an aqueous solution was studied by the potentiometric method. It was shown that the reaction proceeds as the second order process. The rate constants of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion were determined and are 1.46, 2.3, and 3.17 l/(mol.sec) at 30, 35 and 40° С , respectively. The activation energy of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion is 61 kJ/mol, the entropy of activation is –63 J/(mol К ), and the enthalpy of activation is 58.5kJ/mol. It was determined that 2,4,6-trimethylaniline is not prone to oxidative polymerization. This indicates that cation-radicals of aromatic amines which act as active centers of aniline oxidative polymerization are formed. The fact that there is no autoacceleration during oxidation of 2,4,6-trimethylaniline hydrochloride indicates that the oxidative polymerization of aniline is an autocatalytical process.
66-70 59
Abstract
Based on the IR spectroscopy data and on the analysis of rheological characteristics of polypyrrole aqueous suspension stabilized with poly-(N-vinylpyrrolidone) we conjecture that a physical lattice composed with poly-(N-vinylpyrrolidone) is formed, where the lattice points are the polypyrrole chain aggregates interlaced with poly-(N-vinylpyrrolidone) chains. It was shown that there is a hydrogen bond between the constitutional repeating units of poly-(N-vinylpyrrolidone) and polypyrrole. It was determined that the size of the particles of the disperse phase decreases with the increase of poly-(N-vinylpyrrolidone) molecular weight. It was also determined that the size of particles increases with the increase of the mass fraction of polypyrrole aqueous suspension. It was shown that the disperse phase particles are rod-like, and the increase of molecular weight of poly-(N-vinylpyrrolidone) in an aqueous solution results in additional lengthwise stretching of particles. It was also shown that the viscosity of the stabilized poly-(N-vinylpyrrolidone) aqueous suspension follows the Einstein law.
71-76 35
Abstract
The process of pyrolysis of methyl chloride is investigated over various silicoaluminophosphates: pure SAPO-34 phase; modified Fe2O3 (SAPO-34Fe); modified SiO2 (SAPO-34Si); modified by magnesium (SAPO-34Mg). Methyl chloride to ethylene reaction was carried out using a fixed bed reactor with the following conditions. The feed rate (WHSV, equivalent to the mass of methyl chloride) was in the range of 2.52–8.52 h−1, time on stream (TOS) = 2 h, and temperature 425 and 450º С . It is shown that in the presence of these catalysts the process of pyrolysis of methyl chloride is carried out with selective formation of ethylene. It was observed that the initial activity of the catalysts decreases with TOS. The same order of deactivation of catalysts is practically observed: SAPO-34Mg > SAPO-34Fe> SAPO-34Si> SAPO-34. The positive effect of coke buildup on the selectivity of ethylene formation was observed for all samples of the catalyst. The observation was made for an increase in selectivity to ethylene when the feed rate was increased. Catalyst SAPO-34 gives high initial activity (degree of methyl chloride conversion: 80%), it has longer lifetime as compared to the other samples of the tested catalysts. Selectivity of ethylene formation over this catalyst is up to 50–54% mol.

CHEMISTRY AND TECHNOLOGY OF MEDICINAL COMPOUNDS AND BIOLOGICALLY ACTIVE SUBSTANCES

77-80 54
Abstract
It is known that some synthetic polymers can enhance the stability of some proteins including enzymes against thermal denaturation. An important example of such behaviour is poly-N-vinylcaprolactam (PVC), although the mechanism of this phenomenon is not fully understood. This paper deals with this problem with the system PVC-trypsin as an example. PVC is a polymer, which has lower critical solution temperature (LCST) in aqueous solution. It is shown that the rate of enzymatic hydrolysis of a substrate – benzoyl arginine – n-nitroanilide (BAPNA) – with trypsin in aqueous solutions of PVC at 25ºC is higher than that in the buffer solution. It is supposed that this effect is a consequence of the complex formation of trypsin with PVC affecting the conformation of the protein and binding of the substrate. The complexation brings about a decrease of the Michaelis constant and an increase of the rate of the biocatalyst interaction with the substrate. It is found that the activity of trypsin depends on the ratio of the enzyme to the substrate. The complexation of trypsin to poly-N-vinylcaprolactam can have influence on the enzymatic activity of the protein at temperatures above LCST, as well as on trypsin trapping in the precipitating polymer. It is noted that, when one determines the enzyme activity by spectral methods, it is necessary to take into account the possibility of complex formation of the polymer with another substance in the reaction system, which can cause errors.
81-86 34
Abstract
A block-modular synthesis of thiamonomethine dyes – effective photosensitizers – was explored. For the first time the method of differential scanning calorimetry was applied to determine the thermophysical characteristics of monomethinecyanine dyes.
87-95 34
Abstract
The solid-phase synthesis of a tetrameric model sequence of polyamide nucleic acid mimetics (PANAM) incorporating terminal chiral and charged unit was performed. As a result during the synthesis and cleavage from the resin the tendency of PANAM with the N-terminal negatively charged monomer to cyclization with simultaneous N-acyl transfer of carboxyethyl base residue was found. Application of MALDI-TOF mass - spectrometry allowed us to find suitable conditions for obtaining PANAM oligomers without the significant amount of by-products.
96-102 58
Abstract
Ways of improving the theoretical and methodical foundations of management of organizational development of chemical enterprises are considered.
103-105 46
Abstract
The article reveals the contents of ecological-economic information which is necessary for economic growth in the field of nature management preserving the ecological sustainability of the biosphere. It is shown that violation of the bio-geo-chemical unity of the biosphere results in ecological diseases. Besides, the economic efficiency of production slows down due to the increase of ecological-economic costs. As a solution of the issue the author`s position for including standards of cosmic ecology into ecological-economic information is proposed.
106-111 42
Abstract
The influence of substances containing biogenic elements (potassium chloride, sodium phosphate, ammonium nitrate, potassium and urea nitrate) on phytoextraction degree of cadmium from soil by cultivated oat (Avena sativa L.), cutting lettuce (Lactuca sativa L.) and charlock (Sinapis arvensis L.) has been investigated. As the results of experiment the factors used for estimation of relationship between the environment and a physiological role of a chemical element, and also for revealing of its share in biotic turnover and of a role of organisms-indicators and organisms-concentrators have been calculated: phytotoxic effect and factor of biological absorbing of cadmium by plants. It is shown that potassium nitrate promote the extraction of cadmium from soil in a greater degree in comparison with other substances containing biogenic elements.


ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)