The purpose of this work is to study the influence of the electric field strength of an electromagnetic wave with the maximum modifying effect on an epoxy basalt-filled oligomer, which is of great scientific and practical importance for the development of microwave oligomer modification technology. The optimal modes of microwave modification, under which the highest values of the mechanical properties of an epoxy basalt-filled polymer composite material are obtained, are identified: power of 400 W and an exposure time of 24 s. At the same time, the breaking stress in bending increases by 20%, the impact strength increases by 2 times, and hardness increases by 31%. A slight increase of 4.5% in heat resistance is noted compared to the composite obtained on the basis of an oligomer unmodified in the microwave electromagnetic field. The results of resistance to various aggressive environments are obtained, which show that the studied physical and mechanical characteristics of the epoxy basalt-filled material after exposure to an aggressive environment decrease by less than 14%, which corresponds to their good resistance to an aggressive environment. It is established that the effect of the microwave electromagnetic field on an epoxy basalt-filled oligomer is an effective modification method that improves physical and mechanical characteristics with a high level of temporal stability to climatic influences, with a coefficient of property retention of more than 90%.

This paper presents modeling data to select the optimal industrial unit for the microwave modification of an epoxy basalt-filled oligomer (EBO) at electric field strength E of an electromagnetic wave equal to 11.9 × 10³ V/m and a uniform distribution of the temperature field over the entire volume of the modified object. A mathematical description of the electrodynamic and thermal processes occurring in the object under consideration subjected to microwave exposure includes the Helmholtz equation for the electric field strength vector and the heat conduction equation. The joint solution of this problem in a three-dimensional formulation is based on the use of the finite element method, which in this work was implemented in the COMSOL Multiphysics^® 6.1 software environment. According to the modeling results, the use of microwave chambers with a traveling wave of a waveguide type is inefficient because the required value of the electric field strength E is not achieved, while the modeled microwave chamber with a traveling wave on a quasi-coaxial waveguide makes it possible to achieve the required value of the electric field strength E and uniform distribution of the temperature field over the entire volume of the modified object by reducing the generated power for the modification of an EBO from 400 W up to 300 W. Optimal parameters for modifying an epoxy basalt-filled oligomer in the microwave electromagnetic field in the working chamber with a traveling wave on a quasi-coaxial waveguide have been developed, which provide a uniform microwave modification of an EBO with a microwave installation capacity of 11.6 kg/h. A sketch of an industrial microwave working chamber has been developed, which provides a mode of the uniform modification of the oligomer at electric field strength E = 12.3 × 10³ V/m. The proposed microwave chamber with a traveling wave on a quasi-coaxial waveguide can be replicated for the microwave modification of filled oligomers of various chemical compositions.

To enhance the physicochemical and mechanical properties of basalt fiber reinforced epoxy polymer (BFREP), various electrophysical methods, including microwave electromagnetic field processing, have been employed. This study establishes the efficacy and utility of using a microwave electromagnetic field to modify a basalt-filled epoxy oligomer under specific processing conditions (microwave power: 400 W; processing time: 24 s). Microwave processing results in a significant improvement in the mechanical properties of BFREP. The impact strength increases by 2.5 times, Brinell hardness by 78%, and transverse rupture stress by more than twice. The oxygen index and mass loss during ignition in air remain practically unchanged, with a slight increase in heat resistance (4.5%) for BFREP treated with the selected microwave electromagnetic field mode. Thermal stability analysis reveals an increase in coke residues and a shift of the destruction stage to higher temperatures for the microwave-treated basalt-filled epoxy polymer. The modified epoxy-based composites exhibit reduced water absorption and enhanced chemical resistance, indicating the formation of a denser and less defective structure. IR spectroscopy confirms the modifying effect of microwave processing on the interaction between the basalt filler and epoxy polymer. Thus, the microwave electromagnetic field has proven to be an effective technique for modifying the structure of basalt-filled epoxy oligomer. This modification approach significantly enhances the physicochemical and mechanical characteristics of the resulting polymer composite material.

Basalt, known for its unique properties, is used for the production of yarns, fabrics, nets, and heat-insulating wool. Currently, a research is promoted on applicability of basalt as a dispersed filler for thermo- and rectoplastic materials without processing it into fibers. Therefore, investigation into interaction of epoxy binder with the crushed basalt is promising, which determines the aim of the given study. The objects of the research are the epoxy resin ED-20, polyethylene polyamine PEPA, and dispersed basalt filler. Spectrophotometer "Specord" with the IR-spectrum covering the area of 400 ÷ 4000 cm-1 was used to study the interaction of basalt filler with the epoxy oligomer and hardener. To take the photos of IR spectra of powders, the latter are pressed together with an excess of potassium bromide into tablets several millimeters thick. Special vacuum molds and pressure of several tons per 1 cm2 are used to produce the tablets. The ICS data confirm the interaction of ED-20 not only with PEPA, but also with the dispersed basalt. Amino groups, epoxy rings, CH groups of epoxy and aromatic rings of the binder and hardener undergo a reaction. As the content of the basalt filler in the epoxy increases, the same absorption maxima and bands are observed as in the IR spectra of the composite material with a low content of dispersed basalt. The difference is that the higher the basalt content in the epoxy matrix, the higher the relative intensity of such maxima, which indicates a stronger interaction of the components.

В настоящее время актуальным является разработка высокоэнергетических радиопоглощающих материалов, которые обладают свойствами как радиопоглощающего так и высокоэнергетического материала и характеризуются высокой интенсивностью диссипации СВЧ-энергии, что обеспечивает таким композитам специфические области применения для задач оборонно-промышленного комплекса и гражданской промышленности. Одной из основных задач в работе является исследование процесса диссипации энергии при воздействии СВЧ-излучения на высокоэнергетический радиопоглощающий материал. Для решения поставленной задачи проведено численное моделирование в программной среде COMSOL Multiphysics® процесса нагрева диэлектриков в СВЧ электромагнитном поле с целью выбора оптимальной конструкции ВРК, обеспечивающей заданные функциональные свойства композитов В качестве материалов матрицы использованы эпоксидная смола ЭД-20 и фторопласт Ф-4, а в качестве поглощающего наполнителя SiC, который выдерживает высокие температуры нагрева без химического разложения. В работе проведено математическое моделирование распределения температурного поля в высокоэнергетическом радиопоглощающем композите с поглощающим наполнителем, имеющим форму плоского слоя (слой-наполнитель) при различных условиях внешнего воздействия СВЧ электромагнитного поля. Установлено, что высокие показатели диссипации СВЧ-энергии достигаются при нагреве слоя-наполнителя выше 600 0С и высокой скорости нагрева 9,7 – 17,2 0С/с при расположении слоя-наполнителя толщиной 1-4 мм перпендикулярно вектору Пойтинга S и параллельно вектору напряженности Е.

This study presents a novel approach to analyzing high-energy radio-absorbing composites (HRCs) by combining computational modeling and experimental measurements of temperature field distribution under microwave irradiation using a waveguide-based setup. Unlike previous studies that mainly focus on nanofillers or bulk dielectric properties, our work investigates the thermal response of a composite with a single macroscopic SiC sphere (d = 20 mm), embedded in epoxy resin (ED-20) and fluoroplastic (PTFE) matrices, both as an individual sphere and in grouped configurations. This setup enables direct observation and modeling of localized heat accumulation and dissipation pathways. Temperature distributions were examined in filler and at a boundary of filler-matrix at various distances from the filler–matrix interface under different power levels and thermal boundary conditions in ED-20 and PTFE. The results demonstrate that the ED-20 matrix with a 20 mm SiC filler offers an optimal balance between microwave energy absorption and thermal stability. However, at power inputs above 400 W and heating rates exceeding 10 ° C/s, signs of thermal degradation and matrix damage were observed. These findings provide new insights for the design of thermally robust, structurally optimized HRCs with tunable electromagnetic performance.