Antimicrobial lyocell fiber prepared from cellulose pulp grafted with antimicrobial agent.

In this study, dodecyl(triphenyl)phosphonium bromide was successfully grafted onto cellulose molecules of bamboo pulp by ionic interactions, which was confirmed by infrared spectroscopy. This modification significantly improved the solubility and spinnability of the pulp. Subsequently, antimicrobial lyocell fibers were prepared from the modified pulp through a dry-jet wet spinning process. Surface morphology, mechanical properties, crystallinity, antimicrobial performance, dyeing properties, moisture absorption, and wash durability of these fibers were systematically investigated. Experimental results confirmed that incorporation of antimicrobial agent did not significantly affect the surface morphology and crystallinity of the fibers, but it effectively enhanced their mechanical properties. Specifically, the breaking strength increased from 3.57 to 3.80 cN/dtex, and the breaking elongation improved from 6.13 % to 7.33 %. These fibers exhibited antimicrobial activity against E. coli, S. aureus, and C. albicans, with inhibition rates of 99.97 %, 99.99 %, and 99.92 %, respectively. Furthermore, the antimicrobial fibers exhibited excellent dyeing properties, moisture absorption, and wash durability. Notably, even after 50 washing cycles, the antimicrobial agent in the lyocell fibers retained stable bonding. This study provides a theoretical basis and a novel strategy for fabricating functional lyocell fiber.