Study of the operational characteristics of fireproof coatings based on epoxy resins modified with astralenes

Introduction. The aim of the research was to study the effect of carbon nanostructures – astralenes on the opera­tional characteristics of flame retardant intumescent compositions (FRIC), as well as to establish the relationship between the flame retardant efficacy of modified intumescent coatings on their thermal stability, adhesive strength and electrophysical properties.

Materials and research methods. The flame retardant intumescent composition “Thermobarrier” 2 based on ­epoxy resins with astralenes under conditions of electrophysical modification was used as an object of study. The experimental part includes the study by the method of synchronous thermal analysis, the measurement of ­dielectric permittivity, the determination of adhesion by the separation method, the interconnection of the pro­perties of FRIC from the modification conditions by the method of neural network modeling, the determination of the fire retardant efficiency of coatings in the conditions of hydrocarbon flaring.

Research results. FRIC with astralenes at a concentration of 0.1 % by vol. modified under the influence of an alternating low-frequency field has improved operational characteristics: the time when the limit temperature of the surface to be protected increased from 65 to 96 minutes, the adhesive strength increased by 38 %, the oxygen index increased by 11 % compared to the base composition. At the same time, exothermic peaks in the tempera­ture range of 550–700 °C shifted to the domain of larger values by 85 °C, in comparison to the basic composi­tion. Under electrophysical exposure, a regular arrangement of astralenes in the material occurs, as evidenced by a decrease in the dielectric constant of the coating by 45 %, in comparison to an unmodified composition.

Conclusions. Modification of the flame retardant with astralenes leads to an increase in fire retardant efficiency, adhesive strength, thermal stability, a decrease in the flammability and permittivity of the FRIC, provided that the astralenes are uniformly distributed in the coating at a concentration of 0.1 % by vol. The results of neural net­work ­modeling permit to make a conclusion that the physicochemical mechanism of increasing the operational characteristics of FRIC with astralenes introduction and electrophysical effects is associated with the uniform distri­bution of carbon nanostructures in the polymer matrix, a decrease in combustibility with an increase in the adhesive strength of the coating. The data of the research results reflect the possibility of using astralenes as a component of the formulations to increase the operational characteristics of FRIC based on epoxy resins under the conditions of flaring hydrocarbons combustion.

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