Influence of polypropylene fibers on preparation and performance of Fe-modified PAN/PP blended yarns and their knitted fabrics

Abstract

Five blended yarns were spun with polyacrylonitrile (PAN) fibers and polypropylene (PP) fibers at different blending ratios, and then knitted into fabrics. The obtained blended yarns or knitted fabrics were modified using successive amidoximation and coordination with Fe3+ ions to prepare the Fe-modified PAN/PP blended yarns or knitted fabrics. They were used as the heterogeneous Fenton catalysts for the degradation of a typical azo dye, Reactive Red 195, to investigate the effect of fiber blending ratio on the modification, as well as mechanic and catalytic performance. The results indicated that increasing PP fiber content led to a linear increase in the conversion degree of cyano groups to amidoxime groups and Fe content fixed on the surface of PAN fibers in the blend yarn or fabric. PP fibers showed a significant effect on the breaking strength and elongation at break of the blended yarn, and a critical PP fiber content was found to obtain minimum values for strength and elongation. This is due mainly to a large difference in extensibility between the two fibers. The strength and elongation of the obtained knitted fabric were greatly improved by the addition of PP fibers. On the other hand, the blended yarns and knitted fabrics with higher PP fiber content exhibited comparatively stronger catalytic activity.