Magnetically active composite cellulose fibers



A process has been developed for manufacturing magnetically active composite fibers of cellulose using N-methylmorpholine-N-oxide as a direct solvent for this natural polymer. Owing to its elasticity and stability, the process made it possible to add considerable quantities of modifier (up to 50% of fiber weight) to spinning solutions. The incorporation of powdered hard ferrites (barium ferrite) into the polymer solution resulted in fibers with magnetic properties, which exhibited a uniform distribution of the modifier. The results of testing the magnetic properties of the fibers obtained have shown that the coercive force of fibers do not depend on the modifier content, while the residual magnetism increases with the content of the ferromagnetic material. The value of fiber remanence is a fraction of the value of magnetic material remanence, corresponding to its volume content in fibers. This may indicate that the modifier used is chemically stable in the spinning solution medium. The thermal analysis of the fibers (DSC and TGA) has shown no negative effect of the modifiers on the fibers' thermal stability. An undesirable influence of the ferromagnetic compound on the fibers is the deterioration of their mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1529–1534, 2006