Study of Phosphorus-Containing Silica Coatings Based on Liquid Glass for Fire Protection of Textile Materials

Abstract

By introducing, in addition to phosphorus, nitrogen and halogens into the structure of the organosilicon compound, a synergistic effect of the flame retardant effect of the fabric is achieved, but the issue of protecting the environment from the effects of thermal decomposition products of the flame retardant composition arises. In view of the numerous publications on the impact of thermal destruction products of flame retardants on the ecological state of the environment, the problem of finding safe types of flame retardants that do not release toxic decomposition products during thermal destruction has arisen. The aim of the work was to develop a phosphorus- and nitrogen-containing silicate fire-retardant composition based on safe components that do not produce toxic products during thermal destruction of the treated fabric. As a result of the conducted research, it was established the possibility of using modifying additives (orthophosphoric acid and ammonium dihydrogen phosphate) in the composition of protective sol based on liquid glass. It was established that the introduction of small additions of orthophosphoric acid into the SiO2 sol contributes to the formation of continuous thin silica films on the surface of the fibers of cotton fabric threads and significantly increases the time of the beginning of the destruction of the fabric under the action of fire. A positive result was achieved under conditions of single impregnation with sol of low concentration (8 % SiO2). It has been established that the addition of ammonium dihydrogen phosphate also has a positive effect on increasing the flame retardant properties of the fabric. The optimal range of concentration of the solution of the phosphorus-containing additive is 10–15 %. Additional impregnation with a flame retardant solution increases the fire-resistant properties of textile materials and prevents final burning and smoldering.