Silicon protective coatings for textile materials based on liquid glass

The problem of development of technological principles of obtaining silica coatings on the basis of stable concentrated SiO2 sols on the basis of liquid glass is solved in the work. The composition was developed and SiO2 sols based on liquid glass of technical purity were obtained by mixing a solution of liquid glass and acetic acid. Experimental coatings on tissues were prepared by the bath method. After applying each coating layer and removing excess sol, the experimental samples were dried by heating in an oven at (60–80) ºС. The resulting silicic acid solution is characterized by pH5-6, has sufficient resistance to coagulation for about an hour. To improve the quality of impregnation of fabric threads with the composition, ethanol was added in the amount of 5 to 15 vol. %. The obtained compositions were examined by spectrophotometric (CPK-2) and microscopic (Digital Microscope S10) 1000x methods of analysis. The behavior of experimental sols in the induction period of maturation was studied and it was found that the viability of sols increases with increasing alcohol content. It is shown that small amounts of alcohol lead to a decrease in the buffer capacity of the composition and, accordingly, to a decrease in the viability of sols. The alcohol content of 15 vol. % significantly increases the survivability of the sol. The influence of alcohol content on fire-retardant properties of impregnated tissue samples was studied. It has been shown that regardless of the concentration of the SiO2 sol, 10 % ethanol must be added to the composition to improve the fire-retardant properties of the impregnated tissues. After the fire tests, the fabrics have a fairly dense structure, but all the threads have become much thinner. All samples did not lose their elasticity, the coating did not crumble. Given that the stability of impregnated fabric samples compared to non-impregnated samples increased 5–7 times, it can be concluded that the use of SiO2 sols based on liquid glass for fire protection of textile materials is promising.