ИСТИНА

Structural-mechanical modification by the mechanism of solvent crazing is one of the effective methods for obtaining functional fibrous materials. Plastic deformation of fibers in liquid adsorption active medium (AAM) that wets the fiber surface leads to the formation of oriented and dispersed polymer fibrils separated by microvoids. The microvoids are 1–100 nm in size and are filled with the surrounding medium. If AAM contains nonvolatile additives, they are imbibed and remain inside the fiber after evaporation of the solvent. Since the dissolved compounds are introduced into the fiber by the imbibition in the pores and retained inside the fiber for steric reasons, chemical or thermodynamic compatibility of the additive and the polymeric material is not necessary. It was determined that uniaxial deformation of fibers based on PLA in water-ethanol solutions with an ethanol concentration of more than 30-40 wt% proceeds to the high tensile strain of 400-600% via the mechanism of crazing and is accompanied by crystallization of polymer fibrils formed in crazes (the degree of crystallinity reaches 40%). Simultaneously with the development of a highly disperse fibrillar-porous structure, an imbibition of antiseptic substances (iodine, brilliant green, carbol fuchsin) from AAM to fiber occurs. The modified fibrous materials obtained in this work can be promising for the use in the medicine as the bioresorbable suture materials with a biological activity.