In-situ preparation of layered zinc N, N’-piperazine (bismethylene phosphonate) functionalizing reduced graphene oxide for epoxy resin with reduced fire hazards and improved thermal/mechanical properties

Abstract

Layered zinc N, N’-piperazine (bismethylene phosphonate) functionalizing reduced graphene oxide (rGO@ZnPB) was prepared via in-situ method for the reduction of fire hazards of epoxy resin (EP), as well as the improvement on its thermal and mechanical properties. The results reveal a better flame retardancy of rGO@ZnPB than either rGO or ZnPB at the same loading level for EP. Remarkably, EP with 5.0 wt% rGO@ZnPB succeeds to UL-94 V-0 rating, as well as reductions by 38.7%, 30.5%, 33.7% and 33.8% in the peak heat release rate, total heat release, total smoke release and the peak CO production rate, respectively with respect to that of pure EP. Additionally, the thermogravimetric and differential scanning calorimeter results manifest that the thermal stabilities and glass transition temperatures of EP/rGO@ZnPB composites are improved to some extent. Moreover, the incorporation of a small quantity of rGO@ZnPB has some reinforcing effect on the mechanical properties of EP.