ИСТИНА

Polylactide (PLA) is an environmentally friendly and non-toxic commercially available biopolymer. Owing its ability to the bioresorption, PLA is promising for use as the matrices of functional nanocomposites, which are found their application as a suture material, implants, a packaging material, etc. Here we propose an approach to the preparation of multifunctional materials with the required level of mechanical properties and characterized by nanometric mutual dispersity of thermodynamically incompatible organic or inorganic fillers and the polymeric matrix using the crazing mechanism. Uniaxial tension of PLA films and fibers in the presence of different liquid media (hydrocarbons, aliphatic alcohols, water-ethanol mixtures) was carried out via crazing mechanism and accompanied by the formation of finely dispersed and oriented fibrillar-porous structure with a diameter of pores and fibrils of 12-27 nm and a volume porosity of 60 vol%. In this case, a significant increase in the PLA deformability in the liquid media under investigation was observed to the extent of 550% owing to the low-temperature (room temperature) crystallization of the formed fibrils and their hardening. Loading PLA films or fibers by functional components was carried out either during crazing (brilliant green and carbol fuchsin (d), iodine (c), starch) [3] or by the counter-diffusion method (calcium phosphates (a, b)) [4]. The formation of second component particles was occurred directly in the nanopore volume of a polymer matrix. The filler content was up to 30 wt%. It was found, the nanocomposites containing starch and calcium phosphates were promoted the processes of an osteoblast proliferation and differentiation. PLA-based fibers containing iodine were shown bacteriostatic properties for gram-positive actinobacterium Rhodococcus erythropolis X5. So, the approach suggested for the modification of PLA films and fibers by fillers with desired functionalities (phosphates, dyes, antiseptics) widens the spectrum of PLA-based materials applications. The reported study was funded by the Russian Foundation for Basic Research according to the research project №18-29-17016.