Structure Stability, Flame Retardancy, and Antimicrobial Properties of Polyurethane Composite Nanofibers Containing Tannic Acid and Boron‐Doped Carbon Nanotubes

Abstract

AbstractA polyurethane (PU) composite nanofiber with superior flame retardancy and antimicrobial property is developed through the simultaneous incorporation of boron‐doped carbon nanotubes (CNTs) and tannic acid (TA), resulting in excellent thermal, mechanical, and eco‐friendly flame‐retardant properties. The tensile strength and peak heat‐release rate of the composite nanofiber increase with increasing filler content, with the optimal performance (7.38 ± 1.04 MPa and 254 W g−1) being achieved at 3 wt% filler. Using a series of analytical techniques, it is demonstrated that the nanostructure of the neat PU completely collapses upon heating, transforming into a film‐like structure; in contrast, a higher loading of nanofiller leads to a higher heat‐shielding capability, thereby facilitating preservation of the composite nanofiber structure. Finally, the antibacterial activity is shown to increase as a result of the synergic effect of the boron‐doped CNTs and TA.