Improved anti-oxidation properties of electrospun polyurethane nanofibers achieved by oxyfluorinated multi-walled carbon nanotubes and aluminum hydroxide

Polyurethane fibers were fabricated using an electrospinning method with aluminum hydroxide and multi-walled carbon nanotubes (MWCNTs) as flame-retardant additives to improve the thermal oxidation stability of the polyurethane fibers. The MWCNTs were incorporated into the polyurethane fibers after oxyfluorination treatment to improve the dispersivity and compatability. The thermal properties and anti-oxidation stabilities of these polyurethane fibers were investigated under nitrogen and oxygen flows from room temperature to 600 °C to determine the effects of the MWCNTs and aluminum hydroxide additives. The aluminum hydroxide acted as an energy storage tank by releasing water, resulting in an endothermic reaction. The MWCNTs promoted the formation of a charred layer that acted as a protective film to prevent the decomposition of the polyurethane by oxygen radicals. The flame-retardant properties were also improved by an enhanced gel-type structural network generated by the MWCNTs. The integral procedure decomposition temperature and activation energy increased significantly, indicating that the flame-retardant properties of the polyurethane fibers improved. These results are attributed to the aluminum hydroxide, MWCNT additives, and the oxyfluorination treatment.