Bio-inspired adenosine triphosphate-modified h-BN-based coral-like CuAl-LDH nanosheets as a functional green flame retardant to improve the fire safety of epoxy resins via catalyzing intumescent char formation

Abstract

High flammability and fire toxicity are the biggest hindrances to further applications of epoxy resins (EP). In this work, we designed a novel “integrated” green intumescent flame retardant via bio-inspired adenosine triphosphate modification of h-BN-anchored coral-like CuAl-LDH nanosheets (mBN@LDH@PATP). Then, the mBN@LDH@PATP was used as a filler to improve the fire safety of EP. Specifically, the anisotropic heat transfer mode of h-BN can effectively promote the longitudinal barrier and lateral diffusion of heat. The coral-like CuAl-LDH can successfully promote the catalytic carbonization of pyrolytic volatiles and their adsorption. Furthermore, adenosine triphosphate (ATP) synergistically interacts with h-BN and CuAl-LDH to impart a high heat-stable intumescent char network to EP. As expected, mBN@LDH@PATP significantly improved the flame retardancy and smoke suppression of the EP nanocomposites. Compared with the control EP, the prepared mBN@LDH@PATP/EP showed a 43.3 %, 40.8 %, 36.5 % and 39.1 % decrease in PHRR, THR, PSPR and TSP, respectively. In addition, CO and CO2 yield were significantly reduced by 53.5 % and 57.5 %, while LOI (32.9 %) and UL-94 (V-0) were significantly improved. The enhanced fire safety of EP nanocomposites was confirmed by adequate characterization. This research offers a workable way to achieve efficient and environmentally friendly flame retardant polymers.