STUDY OF FOAMING PROPERTIES OF ALKYL SULPHATES IN THE DEVELOPMENT OF FORMULATIONS OF S-TYPE FOAMING AGENTS FOR FIRE EXTINGUISHMENT

По итогам Международной конференции «Проблемные и актуальные вопросы пенного пожаротушения» было принято решение провести анализ рецептур пенообразователей, разработанных специалистами ФГБУ ВНИИПО МЧС России начиная с 1970 г. Полученные в результате анализа выводы будут направлены организациям, заинтересованным в производстве пенообразователей. В статье представлены результаты исследований пенообразующих свойств первичных и вторичных алкилсульфатов, используемых при разработке рецептур пенообразователей типа S для тушения пожаров. The article presents the results of research of foaming properties of primary and secondary alkyl sulfates used in the development of formulations of S-type foaming agents for fire extinguishment. The use of alkyl sulfates is due to several reasons that are very important for fire extinguishing concentrates: low cost, high foaming capacity, high biodegradability. On the basis of common methods of assessment of colloid-chemical and foaming properties, there have been conducted studies in homological series of the most promising biodegradable surfactants: primary alkyl sulfate produced by sulfurizing individual primary alcohols with a number of carbon atoms ranging from 6 to 18; secondary alkyl sulfate produced by sulfurizing individual olefins with a number of carbon atoms from 6 to 18. It has been determined that it is most appropriate to use fractions of anionic surfactants containing homologues with the optimal length of hydrocarbon radicals to produce resistant fire-fighting foams. For primary alkyl sulfates – from C10 to C13; for secondary alkyl sulfates – from C11 to C14. It is shown that a change in the position of the hydrophilic group and the length of the radicals is possible to regulate the foaming properties of secondary alkyl sulfate. For secondary alkyl sulfate up to C11, they are maximum at the location of the hydrophilic group at the first hydrocarbon atom, and for secondary alkyl sulfate from C13 upwards the position of the hydrophilic group in the middle of the radical is preferred. According to foaming properties on «hard» water, homologs of optimal fractions are arranged in a row: primary alkyl sulfate (low molecular) = secondary alkyl sulfates (high molecular) > primary alkyl sulfates (high molecular) = secondary alkyl sulfate (low molecular).