MONO- AND BIFUNCTIONAL IMPREGNATED FIBER CHEMOSORBENTS FOR RESPIRATORY PURPOSE

Abstract

This paper summarizes the data on the development of import-substituting impregnated This paper summarizes the data on the development of import-substituting impregnated fibrous chemisorbents (IFCS) intended for equipping gas cleaning equipment and personal respiratory protection equipment against gaseous toxicants of various chemical nature. To obtain IFCS of the basic gases (ammonia, organic amines), aqueous solutions of polybasic acids (citric, tartaric and hydroxyethylenediphosphonic) are used as impregnating reagents. IFCS absorb toxicants due to neutralization reactions. The absorption of ammonia and amines of IFCS obtained by impregnation of fibrous carriers (FC) with aqueous solutions of 3d-metals (Ni2+, Co2+ and Cu2+) salts occurs due to complex formation reactions. To obtain IFCS of acidic gases, aqueous solutions of sodium carbonate and urotropine (HMTA) containing structuring additives were used. Impregnating aqueous solutions based on monoethanolamine (MEA) and polyethylenepolyamine (PEPA) have also been developed using their non-volatile derivatives with a higher molar mass. A significant improvement of the IFCS protective characteristics was achieved by introducing of various modifying additives – promoters into the composition of these solutions. Single-layer IFCS -ampholytes (IFCS-A) for respiratory purposes have been developed, which depending on the circumstances are able to absorb both acidic and basic gases (vapours), for example SO2 and NH3. Impregnation solutions include complex compounds of 3d-metals (Ni2+, Co2+ and Cu2+) with MEA, ethylenediamine, HMTA and PEPA at various molar ratios of components or buffer mixtures based on polybasic acids and organic bases (MEA and PEPA) of medium strength salts. Chemisorbents for acidic and/or basic gases (IFCS-I, IFCS-AI) have been developed, the moment of “response” of the dynamic absorption capacity of which can be visually determined by the change in color of the gas mask elements during the “breakthrough” of the sorbate, obtained by impregnating of FC with solutions containing acid-base indicators.