Construction of hetero-structured fillers to significantly enhance the fire safety of bio-based nanocomposite coating

As fire safety has become a major security hazard in our daily life, high-performance flame-retardant leather products with excellent smoke suppression are highly desired for applications in vehicles and furniture. In this study, the hetero-structured filler layered double hydroxide-reduced graphene oxide (LDH-rGO) was prepared by an in-situ co-precipitation method. Then, waterborne casein-based LDH-rGO (CA-CPL/LDH-rGO) nanocomposite latex was prepared by solution blending, and finally, the composite latex was sprayed on the leather surface. Vertically aligned LDH nanosheets were anchored on the surface of rGO surface via covalent bonding, synergistically affording a complete two-dimensional (2D) double-layer flame-retardant smoke suppression network and subsequently enhancing the flame retardant of the coated leather considerably. At an LDH-rGO loading of 5 %, the CA-CPL/LDH-rGO coated leather exhibited an excellent limiting oxygen index of 27.4%, an outstanding heat release rate of 146.18 kW/m2, and a good smoke production rate of 1.48 m−2 s−1. Moreover, the mechanical properties of CA-CPL/LDH-rGO coated leather were improved by 71.8% compared with that of leather. The excellent comprehensive performance of makes CA-CPL/LDH-rGO coated leather renders immense application potential in vehicles and furniture.