Sorptive properties of heat-resistant fibers based on aromatic polymers

Conclusions -- A comparative study has been made of the sorptive properties (isotherms and kinetic sorption-desorption characteristics for water vapor and swelling in water) of aromatic heat-resistant and difficultly combustible fibers.-- The sorption isotherms of the fibers Terlon, Fenilon, SVM, Togilen, Oksalon, and Aramid-T have an S-shaped form, which is characteristic of polymers containing hydrophilic functional groups which are able to be hydrated. In the case of Lola fiber, the isotherm has a convex form, which is typical for polymers of low polarity with a porous structure.-- For most of the fibers, the kinetic sorption-desorption curves are characterized by the presence of a section of rapid moisture exchange with subsequent departure onto a plateau. SVM fiber has some differences, where the sorption-desorption process takes place over hundreds of hours because of structural changes (amorphization of structure) on swelling in vapor.-- Polyamidobenzimidazole fibers of the type of Togilen and SVM have the best hygroscopic properties. Among all the forms of aromatic heat-resistant fibers, Togilen is close to cotton, wool, and viscose fibers in hygroscopic properties.-- The structural causation of differences in the sorptive properties of aromatic thermally stable fibers has been examined.Translated from Khimicheskie Volokna, No. 2, pp. 37–39, March–April, 1993.