Nickel modified two-dimensional bimetallic nanosheets, M (OH)(OCH3) (M=Co, Ni), for improving fire retardancy and smoke suppression of epoxy resin

In this study, the two-dimensional bimetallic nanosheets, M(OH)(OCH3) (M = Co, Ni) was used as a novel "nano-flame retardant" to improving fire retardancy and smoke suppression of epoxy resin (EP) nanocomposties. With 3 wt% M(OH)(OCH3) added, the peak heat release of EP/M(OH)(OCH3)-3 wt% decreased from 1021.4 to 867.8 kW/m(2), compared with pure EP. To the smoke suppression, the peak of smoke product rate and the total smoke product of EP/M(OH)(OCH3)-3 wt% was 0.27 m(2)/s and 28.3 m(2), which decreases by 15.6 and 15.0% than those of pure EP, respectively. Only 1 wt% M(OH)(OCH3)@Ni, which got the modification by the introduction of nickel ion on surface, could endow the composite a further improvement in both flame retardant and smoke suppression. The results of gas chromatography-mass spectrometer demonstrated the M(OH)(OCH3)@Ni facilitated the aromatization reaction and promotes the generation of the protective char layer, which hinders the propagation of combustible free radicals and restrains the release of smoke. This study demonstrated that the two-dimensional bimetallic nanosheets, M(OH)(OCH3) (M = Co, Ni), has a great potential to act as novel "nano flame retardant". Moreover, the appropriate modification could further promote its performance in improving the flame ratardancy and smoke suppression of EP.