▎ 摘 要
Graphene (Gr) and poly(ionic liquid) (PIL) modified polyurethane (PU) sponges with enhanced flame-retardant properties were prepared by the direct dip coating of Gr and ionic liquid (IL) monomers onto a PU sponge followed by the polymerization of IL monomers under thermal initiation. With a content of 1.5% Gr in IL, the limiting oxygen index (LOI) of PU-PIL-Gr was 26.1%, whereas the neat PU sponge showed an LOI of only 17.9%. The horizontal flame test results indicate that PIL-Gr prevented horizontal flame spread and eliminated melt dripping. Compared with that of the neat PU sponge, the peak heat release rate of PU-PIL-Gr decreased about 22.0%. These improvements on flame retardancy might have been due to a hybrid flame retardant originating from Gr (which acted as carbon source) and PIL (which contained the flame-retardant elements) in the PU sponge and the formation of protective layers, which isolated the oxygen and heat more effectively. (c) 2017 Wiley Periodicals, Inc.