Search Results (2)

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. Full article

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%. Full article