To reduce the flammability of polymers, functional flame retardants have become widespread, among which phosphorus-containing methacrylates occupy a special place. Despite the well-developed issues of their synthesis and use, the search for new monomers of this class remains a demanding task due to their efficiency, environmental friendliness, and a number of other reasons. This review systematizes the results of recent research concerning phosphorus-containing polymerizable monomers of the methacrylate series, the use of which makes it possible to reduce the flammability of the resulting materials and composites.

This paper presents a study of flammability and downward flame spread rate in an opposed oxidizer flow over glass fiber-reinforced epoxy resin (GFRER) with the added flame retardants 6,6 '-((methylenebis(4,1-phenylene))bis(azanediyl)) bis(6 H-dibenzo[c,e][1,2]oxaphosphinine 6-oxide) (DDM-DOPO) and graphene and with a binder content (BC) of similar to 35 wt% and similar to 52 wt%; the mass ratio of the glass fiber to the binder in the composite was 2:1 and 1:1, respectively. To evaluate the flammability and thermal stability of the obtained materials, the LOI test, the UL-94HB test, and thermogravimetric analysis were conducted. The effective DDM-DOPO concentration for decreasing the flammability of GFRER was found based on the LOI results. During the flame spread experiment with an opposed oxidizer flow, the addition of flame retardants resulted in an increase in the limiting oxygen concentration (LOC). Oxygen concentration increase in the oxidizer flow led to a decrease in the flame retardant effect on the rate of flame spread (ROS) for samples with a BC of similar to 35 wt%. The flame retardant effectiveness for samples with a BC of similar to 52 wt% remained almost the same at 40-60 vol% O-2 concentrations. The relationship among the LOI, LOC, and ROS was experimentally established. A numerical simulation of flame spread over reinforced material was performed using a coupled gas-solid heat and mass transfer model to predict the ROS over GFRER with and without flame retardants. The model correctly predicted the ROS for GFRER with similar to 35 wt% BC, while for samples with similar to 52 wt% BC, the model gave lower ROS compared to experiment.

Objectives. To obtain polymer composite materials (PCM) with enhanced physicomechanical properties using the vacuum assisted resin transfer molding (VaRTM) method, binders must have a viscosity of up to 500 mPa∙s. In some cases, this leads to restrictions on the use of certain materials or requires the use of temporary diluents. This is closely related to the deterioration of other required composite characteristics, such as increased flammability. Three phosphorus-containing oligoester(meth)acrylates PhOEM-1, PhOEM-2, and PhOEM-3 were synthesized with significant differences in viscosity characteristics in the series PhOEM-1 << PhOEM-2 << PhOEM-3. The polymer based on PhOEM-1 exhibits inferior physicomechanical properties despite having lower viscosity. Hence, the aim of the study was to investigate the viscosity characteristics of mixtures of methacrylate binders of the same nature but different structures and functionalities. This was done by studying the rheological properties of the original oligoester(meth)acrylates and their mixtures taken in various ratios. The method used was to optimize compositions via a simplex lattice (Scheffe’s plan), in order to obtain PCM using the VaRTM technology.Methods. The study of rheological properties of phosphorus-containing oligoester(meth)acrylates and their mixtures was conducted using the method of rotational viscometry on a Brookfield LVDV-II + Pro viscometer with a spindle 27 at different shear rates ranging from 0 to 70 s−1 and temperatures from 30 to 70°C. Rheological studies were also conducted on a Lamy Rheology GT300 PLUS (GEL TIMER) viscometer in the same range of shear rates and temperatures.Results. It was established that the objects under investigation can be characterized by viscosity values ranging from 96 to 2137 mPa∙s depending on the temperature. The nature of the viscous flow of phosphorus-containing oligoester(meth)acrylates and their mixtures is similar to that of Newtonian liquids only at certain shear rates. The effective activation energies of the viscous flow of binders and their mixtures were calculated, and the influence of temperature on the viscosity of binders was determined.Conclusions. The study identified the features and nature of the flow curves of phosphorus-containing oligoester(meth)acrylate binders of the same nature but different structures and functionalities, as well as of their mixtures. The optimal composition ranges of threecomponent mixtures of phosphorus-containing oligoester(meth)acrylates for use in the VaRTM technological process in producing polymer composite materials within the temperature range of 30 to 70°C were defined. The optimal compositions and temperature conditions for obtaining polymer composite materials using the VaRTM technology were also identified. This enables the production of polymer products with complex geometric shapes and varying sizes.

The results of the experimental data on the influence of oligourethane methacrylates 2002T and MIFM, as well as epoxy dianic and oil polymer resins, on the values of the contact angle of wetting with a polymer solution on the surface of carbon fibers and the adhesion strength during peel testing of finished prepregs have been obtained. The results indicate that with the presence of oil polymer resin in the impregnating solution, the adhesion strength during peel testing increases threefold (1.68 MPa), while the contact angle of wetting decreases by 28°. The preliminary data obtained allow for modeling the vacuum impregnation process of carbon fibers and generating kinetic curves for different compositions, thereby deepening the understanding of the interaction mechanisms among the components of the system.

Для снижения горючести полимеров широкое распространение получили функциональные антипирены, среди которых особое место занимают фосфорсодержащие метакрилаты. Несмотря на хорошо проработанные вопросы синтеза и их использования, поиск новых мономеров такого класса остается актуальным благодаря их эффективности, экологичности и ряду других причин. В настоящем обзоре систематизированы результаты исследований последних лет, касающиеся фосфорсодержащих полимеризационноспособных мономеров метакрилатного ряда, при использовании которых удается снизить горючесть получаемых материалов и композитов.

The study experimentally proved the possibility of obtaining intermetallic materials of the Ti-Fe system from mixtures of titanium and iron powders using MIM technology and subsequent reaction sintering. It has been established that the structure of such materials is close to stable equilibrium and contains TiFe as the main intermetallic phase.

The oxidative dehydropolycondensation of aniline production waste with up to 30 wt % free aniline with ammonium persulfate or potassium bichromate has been studied. The effects of the component ratio and synthesis conditions on the product yield were examined. The product composition was analyzed by IR spectroscopy. The polymers obtained from potassium bichromate were shown to be characterized by electric conductivity.

The process of oxidation of morpholine and its derivatives by hydrogen peroxide in an aqueous medium has been studied. The effect of component ratios and synthesis conditions on the yield of products was studied. The compositions of the reaction products were confirmed by elemental analysis, IR, chromato-mass spectroscopy, and the physicochemical properties were studied. The possibility of their use as polymerization inhibitors was studied using styrene as an example.

The article raises the problem of environmental pollution and considers the ways to solve it - reclamation of territories affected by man-made activities. The introduction describes the importance of solving the environmental problem in the Russian Federation. The authors cite well-known and promising works of Russian and foreign scientists as an example. The authors analyze soil remediation technologies, their advantages and disadvantages; describe the object of disposal of production and consumption waste - an unauthorized dump on the territory of the Shuvalov industrial zone of Nizhny Novgorod. The article provides a brief history of the landfill, data from the engineering and environmental expertise, including a brief description of natural and man-made conditions, the current ecological situation at the research object. Researchers analyze the level of damage caused to the soil by man-made activities, describe reclamation technologies using natural mineral-organic substances. The authors interpret the results of laboratory studies of soil samples got from the screening of landfill masses, the level of heavy metals in the original samples and after treatment with mineral-organic substances at a certain concentration. A decrease in the content of heavy metals and the hazard class of the studied soil proves the effectiveness of the proposed method. To continue the study, the authors set improving the reclamation technology to get a soil-recultivator that is stable in properties and belongs to the V hazard class. The article considers the possibility of using the resulting soil-recultivator not only for the reclamation of territories disturbed by technogenic activity but also as a building material in the implementation’s framework of energy-efficient and nature-saving technologies.

The effect of dissolved PVC in ED-20 epoxy resin is shown, containing magnesium hydroxosilicate as a filler, as a form of formation of a curable material. The values of impact strength, strength and elastic modulus are estimated depending on the amount of dissolved polymer. Microwave radiation is used to intensify the dissolution of PVC. The possibility of dissolving PVC in epoxy is shown. It is clear that a solution of PVC in the mass of epoxide is able to form a spatially cross-linked polymer structure that changes the final properties of the material.

Новые технологии, Химическая промышленность, Химическая технология, Научные журналы, Защита от коррозии, Технология металлов, Свойства материалов, Технические журналы, Наука и технологии, Справочная литература, Научные разработки

Objectives . To synthesize phosphorus-containing oligoestermethacrylates spatially separated by spacers of aliphatic or aromatic structure and evaluate their effect on photocuring kinetics. Methods . For determining the qualitative and quantitative composition of the synthesized compounds, the following methods were used: thin layer chromatography; chromatographic and mass spectrometry; infrared spectroscopy; 1H, 13C, 31P nuclear magnetic resonance spectroscopy; differential scanning calorimetry. The dielectric loss tangent was determined on a specially designed optical cell with an ultraviolet (UV) light source to an immittance meter. Elemental analysis was performed on an energy dispersive X-ray fluorescence spectrometer. Results . Spatially separated oligoestermethacrylates based on phosphorus trichloride containing aliphatic or aromatic spacers in the structure were synthesized. During the interaction of glycidyl methacrylate with phosphorus trichloride in the mass of the latter, reaction products were shown to be formed both according to the Krasusky rule from the side of the α-carbon atom, as well as against this rule with the formation of isomeric products. Obtaining these compounds in bulk is possible only in the presence of a homopolymerization inhibitor. The influence of the spacer structure on the curing rate of oligoestermethacrylates under the action of UV radiation has been established. It has been shown that the introduction of a spacer into the oligomer structure is accompanied by an increase in the induction period by a factor of 39 compared to a sample without a spacer. Conclusions . The results obtained indicate the possibility of obtaining new oligoestermethacrylates with aliphatic and aromatic spacers in the structure. The influence of the structure of the spacer on the kinetics of photocuring is determined.

The kinetics of the processes of primary hydrogenation of material based on TiFe obtained by explosive pressing of titanium and iron powders with subsequent heat treatment has been investigated. Using the results obtained and mathematical processing of the curves using the Avraami-Erofeev equation, it was revealed that the mechanism of their saturation with hydrogen corresponds to the classical concepts of reaction diffusion. The process begins with the formation of a layer of solid solutions of hydrogen on the surface of the material in the initial phases of the material and after the latent period continues with the formation of a layer of hydride phases. t is shown that the hydrogen storage material TiFe + TiFe has a significantly higher hydrogen capacity than single-phase TiFe.

Обзор посвящен анализу информации по старению эластомеров под действием различных климатических и биологических факторов в наукометрических, информационных и патентных базах данных. Выявлена недостаточность данных о натурных испытаниях эластомеров в условиях тропического климата.

The authors compared the results of determining the ozone resistance (OR) and weather resistance (WR) obtained in laboratory and natural conditions of tropical climate. The samples were manufactured with unsaturated rubbers (nitrile butadiene rubbers BNKS-18AN, BNKS-28AN, BNKS-40AN and SKN-26PVC-30, styrene butadiene rubber SKMS-30 ARKM, isoprene SKI-3 and butadiene SKD-ND). All the samples were not filled with antioxidants or antiozonants. The curing process at 160 °C and the total crosslink density (νt) were studied using a MonTech MDR 3000 Professional rotorless rheometer. The physical and mechanical properties of the vulcanizates were determined with the using of a Zwick\Roell Z010 tensile testing machine at a test speed of 500 mm / min. Hardness and tear resistance were also determined. The numerical estimate of νt was obtained from the data on the dynamic shear modulus. Density of chemical bonds νch was determined from the data of equilibrium swelling in toluene according to the Flory-Rener equation. Full-scale climatic tests in tropical climate in the south of the Republic of Vietnam were carried out for 9 months in accordance with GOST 9.066-76 with initial deformations of 10, 20, 30, 40 %. The sample stand was oriented south, at a 45 degree angle. Cracks formed on the rubber surface were recorded by photography. The time before the onset of fracture Tof and the time until the appearance of the first cracks Tfc were determined. It is shown that samples of rubbers with high OR in laboratory tests had the best WR. A correlation of νch with Tof and Tfc was revealed. The obtained results show the possibility of using the express method for assessing the OR of rubbers in the development of formulations for tropical climates.