Halogen-free flame retardant finishing of ultra-high molecular weight polyethylene fiber

In order to improve the flame retardant properties of ultra-high molecular weight polyethylene (UHMWPE) fiber, carbon microspheres coated by magnesium hydroxide (MH-CMSs), which have both flame retardant and smoke suppression effect, were used as flame retardants, and tetrabutyl titanate and triphenyl phosphite were used as surfactants. The UHMWPE fibers were modified using the procedure of impurity removal-activation-padding-baking. The flame retardant properties, mechanical properties and thermal stability of these fibers were tested, and the flame retardant mechanism was studied. The research results show that this method is able to improve effectively the flame retardancy of UHMWPE fiber without harming its mechanical properties. Compared with pure UHMWPE fiber, the limited oxygen index of flame retardant UHMWPE (FR-UHMWPE) fiber is increased more than 36%, the peak heat release rate is reduced by up to 39.3%. In addition, smoke and molten droplets of the UHMWPE fibers are suppressed, and the fire risk is significantly reduced. The FR-UHMWPE fiber exhibits condensed phase flame retardant mechanism. The flame retardant finishing promotes the degradation of UHMWPE into carbon, which forms a dense and continuous char layer during the combustion process. This char layer can effectively prevent the transfer of heat and mass, and thus has a flame retardant effect. Copyright No content may be reproduced or abridged without authorization.