Carbon nanotubes (CNTs) were used to modify polyacrylonitrile (PAN) polymer. The PAN/CNT composite fibers were spun from dimethylformamide solutions containing different types of CNTs. The effect of nanotube addition to the fiber precursor on the resulting mechanical properties is discussed. In this study, we examined the relationship of the rheological properties of PAN spinning solutions containing various types of CNTs and the tensile strength of the resulting PAN fibers. The presence of CNTs in the PAN spinning solution enhanced its deformability during the drawing stage. This effect resulted in a higher tensile strength in the fibers containing nanotubes, as compared to the pure fibers. The use of a three-stage drawing process resulted in a significant increase in the tensile strength of PAN fibers modified with multiwalled nanotubes.

ABSTRACT:The effects of basic fiber-forming parameters on the porous structure, moisture absorption, and strength properties of fibers from polyimidoamide nanocomposites were examined. Beneficial fiber-forming conditions were established in consideration of the fiber sorption and strength properties. It was found that the incorporation of montmorillonite into the fiber-forming polymer resulted in beneficial increases in fiber porosity and internal surface area.

ABSTRACT:The structural parameters and strength properties of a new generation of polyacrylonitrile fibers have been analyzed. These fibers, after being carbonized, can be used in biomaterial engineering. They are characterized by a high tensile strength of 31-43 cN/tex. An advantageous influence of nanoparticles added to the fiber matter on the degree of crystallinity has been found. When nanoparticles of hydroxyapatite are incorporated into these fibers, their degree of crystallinity increases by about 5%.