FEATURES OF THE INFLUENCE OF COPPER (II) FLUORIDE ON THE COMBUSTI-BILITY OF METAL-COORDINATED EPOXY-AMINE COMPOSITES

Abstract

Introduction. Combustibility is one of the most important indices used to assess the fire and explosion risk of polymer materials under the conditions of transportation, storage, or operation. Since most synthetic polymers have an organic structure, it is almost impossible to create a completely non-combustible polymer material. However, fires are usually caused by low power ignition sources. Therefore, it is extremely important to reduce the combustibility of polymer materials, which will be reflected in the difficulty of their ignition and flame propagation. A number of flame retardant-hardeners obtained based on inorganic salts of transition metals with amine hardeners of epoxy resins are of high efficiency in reducing the combustibility of epoxy-amine composites. Therefore, carrying out systematic studies of the effect of such flame retardants on the fire risk of materials based on epoxy resins is extremely relevant and will make it possible to widen the range of available reactive flame retardants and develop the technology for obtaining flame-resistant epoxy polymer materials.
Purpose. The work aims to experimentally investigate the regularities of the influence of reactive flame retardant - copper(II) fluoride - on the combustibility of metal-coordinated epoxy-amine composites.
Methods. The combustibility of epoxy-amine composites was assessed by the maximum temperature increase, sample mass loss, and time to reach the maximum temperature of gaseous combustion products, which were determined by DSTU 8829:2019 (p. 7.3).
Results. The introduction of copper(II) fluoride into the epoxy-amine composite of flame retardant results in to a noticeable change in the parameters of the combustibility group, that is, a decrease in the maximum temperature increase, mass loss and an increase in the time to reach the maximum temperature. The most resistant to burning turned out to be the composition with the content of the proposed flame retardant of 10 mass parts per 100 mass parts of binding ED/pepa-CuF2(10). According to the indicators of the combustibility group, it belongs to combustible materials. Compared to the unmodified ED/pepa composite, the maximum temperature increase during combustion of the modified ED/pepa-CuF2(10) epoxy-amine composite decreases by 63ºС, the mass loss – by 12.4%, and the time to reach the maximum temperature of gaseous combustion products, on the contrary, increases by 92 seconds.
Conclusion. The results of the carried out studies show the high efficiency of the use of the new reactive flame retardant copper(II) fluoride to reduce the combustibility of epoxy-amine composites. This is primarily due to the formation of strong coordination bonds between the non-combustible inorganic salt and the combustible organic hardener of epoxy resins. It is necessary to spend additional energy on the destruction of these bonds, which results in a decrease in the intensity of the release of volatile combustible decomposition products.