The possibility of modifying polypropylene fibrous materials at the stage of melt spinning through the introduction of composite powders based on metal-containing nanoparticles immobilized in a high-pressure polyethylene matrix during their synthesis has been investigated. It has been shown that the use of immobilized iron-, manganese-, and nickel-containing nanoparticles as a modifier creates conditions which prevent their aggregation during the melt spinning of the polypropylene filament and ensures the retention of stability of sizes of nanoparticles. It has been established that the introduction of metal-containing nanoparticles immobilized in polyethylene into polypropylene at the stage of filament spinning yields the high uniformity of their distribution in the polypropylene filaments.
