Том 15, № 1 (2025)
- Жылы: 2025
- Мақалалар: 18
- URL: https://journals.rcsi.science/2221-7789/issue/view/24388
Бүкіл шығарылым
Physics
An interfacial characteristics of biocomposites «Epoxy polymer/plant fibre»: a fractal model
Аннотация
The interfacial effects in biocomposites (composites reinforced with plant fibres) were studied within the framework of fractal analysis. It has been shown that used methods of fractal analysis allow enough precise quantitative description of the most important characteristics of interfacial interaction polymer matrix- plant fiber, namely, shear strength of interfacial contact and depth of penetration (infiltration) of matrix poly- mer in superficial layer of reinforcing fiber. The fulfilled analysis corresponds fully to results for other types of reinforcing fibers, i.e. plant fibers cannot make in a separate class of reinforcing elements. Diameter of initial fiber serves as basic characteristic for analysis fulfillment.
5-9
The failure mechanisms of biodegradable polymer composites in the conditions of impact loading
Аннотация
The failure process of two biodegradable composites on the base of polylactic acid, reinforced with two types of different natural fibers was studied within the framework of fractal analysis. The fractal di- mension of their structure, controlling failure type and as consequence, the value of energy, adsorbed in condi- tions of impact loading, is the main factor, defining sharp enhancement of impact toughness of these biocompo- sites. The condition of transition from quasibrittle to quasiductile failure serves achievement by fractal dimen- sion of structure of biocomposite the value of 2.7. Interfacial interactions are imposed restrictions on adsorbed in process of impact loading mechanical energy, reducing impact toughness. At large dimensions of biocompo- sites structure (>2.87) in them the effect of superplasticity, i.e. sample is deformed, but not failured in the con- ditions of impact tests.
10-15
Arsenide-silicate glasses formed by oxidation of sih4 and ash3 to diffuse arsenic into si and sio2
Аннотация
The paper studied arsenide-silicate glasses formed by oxidation of SiH4 and AsH3. It has been shown that the precipitation rate decreases sharply when the concentration of AsH3 in the mixture of reagents is more than 10 mol%. The diffusion of arsenic through barrier oxide and without barrier oxide was studied using oxygen O2 and argon Ar as a diffusion medium. It has been shown that the use of oxygen O2 instead of argon Ar as a diffusion medium changes the nature of defects, leads to an increase in the depths of transitions and the surface concentration of arsenic As in diffusion layers. A connection has been found between the concentration of As2O3 in glasses and the tendency to form defects in glass during heat treatment.
16-20
Investigation of the process of destruction of a polyamide composite under dynamic loading
Аннотация
The process of destruction of a polyamide composite with different porosities under dynamic loading has been studied. Graphical dependences of pressure in polyimide with varying degrees of porosity on mass velocity are obtained; impact adiabats of the same polyimide samples in D-u coordinates are calculated. It has been established that irreversible physico-chemical transformations of matter at the shock wave front occur in the polymer composite under extreme conditions.
21-25
Chemistry
Study of comparative characteristics of polyethylene pipe grades.
Аннотация
This article discusses a new class of ethylene-α-olefin copolymers known as PERT (polyethylene with enhanced temperature stability), which exhibit improved physical and chemical properties. These properties include high thermal stability under hydrostatic and hydrodynamic loads, as well as mechanical and diffusion prop- erties. A special feature of PERT is that the required strength at high temperatures is achieved without the need for cross-linking of macromolecules, due to the unique crystalline structure of these materials. Given its versatility, polyethylene PERT is recommended for the production of pipes intended for hot water supply and heating systems.
26-30
Photostabilization of polybutyleneterephthalate with carbon black
Аннотация
The article presents a review of the literature on known methods of photostabilization of poly- butyleneterephthalate, including carbon black. The effect of carbon black on the physical and mechanical properties and resistance of the polymer to UV radiation was studied. The optimal formulation of polymer composites based on polybutyleneterephthalate modified with channel carbon black was established.
77-80
Long-term thermo-oxidative aging of phenolic triazine polymers
Аннотация
Long-term thermo-oxidative aging of phenolic triazine polymers in the air in isothermal condi- tions at wide temperature range was researched. Also powder samples of the polymers were researched by TGA-method. Activation energy of the destruction reaction was evaluated. The dependences «conversion – time» in isothermal conditions were built by calculation. The discrepancy between the calculated and experi- mental curves is shown which is explained by scale effect.
31-36
Obtaining oil from grape seeds and an expulsion of its properties
Аннотация
The features of obtaining grape oil were discussed as a processing product of secondary grape raw materials from organic extract of thin grape seeds. Images are determined quality oil from grape seeds.
The number of extracting oil from grape seeds is theoretically calculated. It is shown that the possibility of ef- fective use of grape oil in the development of a cosmetic product is a hand cream.
37-44
45-48
Study of the influence of mineral fillers and their content on the performance properties of sealants based on nitrile-butadiene rubber
Аннотация
The work carried out a study of various types of mineral fillers (chalk, kaolin, talcum) in the composition of non-curing elastomeric sealing compositions based on nitrile butadiene rubber in order to im- prove such performance characteristics as adhesion to metal, water absorption and oil resistance.
49-52
Optical properties of alkylated amino acids
Аннотация
This paper discusses the optical properties of alkylated amino acids, which affects their spec- troscopic characteristics such as absorption and fluorescence, making them interesting for research in the field of chemistry and biochemistry. The paper analyzes changes in optical properties depending on the length of the alkyl chain and the structure of the substructures, which allows us to identify patterns that affect the interaction of such amino acids with the environment. The potential for the use of alkylated amino acids in optical and sen- sor technologies, as well as in medicine, is also discussed.
53-56
Optimization of the choice of liquid phase material in the production of products from fibrous polymer composite materials with two-phase reinforcement scheme
Аннотация
Justification of the choice of the optimal material of the liquid phase of composites with a two- phase reinforcement scheme was carried out on the basis of solving the multi-criteria problem of optimization by methods of ideal point and uniform optimization when used as the main optimization criteria the results of the experimental studies of these materials on the evaluation of tensile and impact strength, as well as losses of these values under conditions of influence of low negative temperatures (–30 and –50 °C).
57-61
Polymerization of liquid crystal monomers and their mixed compositions with chiral additives
Аннотация
The work is devoted to the preparation and study of the structure and properties of low- molecular liquid crystals and, in particular, monomers with chiral additives of various natures for the forma- tion of chiral nematic mesophases. The possibility of obtaining such phases under conditions of polymerization with reversible chain transfer of mixture compositions with monomers and the study of the properties of the resulting mixtures were studied. Particular attention is paid to the role of chemical interaction between the components of composites from the point of view of stability and preservation of properties by such systems.
62-67
Effect of quaternary ammonium salt formation on polymerization of certain vinyl monomers.
Аннотация
Studies of the polymerization reaction of vinyl monomers in the presence of an initiating system, formed as a quaternary ammonium complex based on amine polymers, such as pyridine-aminated polystyrene, trimethylamine and polyphenyl-ethyl, have been carried out. As a result, it was found that hydrophilic monomers such as acrylamide had the highest polymerization rate. This is due to the fact that the polymer initiator is water-soluble.
68-72
Modification of thermoplasts with a polyfunctional stabilizer
Аннотация
The main criterion that defines the sphere and technical level of use of polymer composite mate- rials are mechanical and thermal properties. The simultaneous strengthening of the polymer matrix and the in- crease in thermal properties is one of the main technological tasks of polymeric material science. In this regard, the development of effective modifiers-stabilizers of thermoplasts is a priority in the chemistry of polymeric mate- rial science.
73-76
Research of the thermomechanical properties of epoxyacrylate oligomer
Аннотация
The article presents the results of the research of thermomechanical properties of epoxyacrylic composition by the method of thermomechanical curves. It was shown that the thermomechanical curves of epoxy acrylates, on the one hand, correspond to the thermomechanical curves of densely meshed
polymers, on the other hand, amorphous thermoplastics. The main thermomechanical properties of the studied oligomeric composition were determined. The influence of the curing system and the monomeric composition on the degree of crosslinking and phase transition temperatures of the cured material was shown.
81-85
Determination of kinetic constants from primary kinetic data of thermal decomposition of condensed materials
Аннотация
The method and results of direct analysis of complex primary kinetic data on the exothermic decomposition of condensed materials without involving the differential form of the kinetic equation are con- sidered. Using the example of data for the thermal decomposition of picric acid, widely used in composite ma- terials, including polymer ones, the effectiveness of the method and the good correspondence of the results ob- tained with the literature data are shown.
86-90
Synthesis of aromatic oligosulfones and block copolyesters based on them
Аннотация
In this work, the synthesis of aromatic oligosulfones of various structures and degrees of poly- condensation was studied in order to obtain block copolyesters with high molecular weight, improved heat- resistant characteristics and high physical and mechanical properties. It was shown that with an increase in the degree of condensation of oligosulfones, an increase in softening temperatures is observed, at which the percent- age of hydroxyl groups simultaneously decreases. To determine the presence of hydroxyl groups at the ends of oligosulfones in accordance with the expected structure, as well as their activity, test syntheses were carried out on the obtained oligosulfones. Some results and elemental analysis data are presented, which, together with IR spectroscopy, confirm the structure and composition of the synthesized oligosulfones. Block copolyesters with high values of reduced viscosity were obtained by the method of acceptor-catalytic polycondensation using phthalic acid dichlorides.
91-95