Intumescent fire-retardant coatings for ancient wooden architectures with ideal electromagnetic interference shielding

Wood is widely used in the field of construction, decoration, and electronics, but its inherent flammability has serious fire hazards. As one of the fire-retardant treatment methods of wood, fire-resistant coatings have greatly reduced and prevented the occurrence of fires in the field of combustible materials. In this work, using melamine polyphosphate (MPP) as intumescent flame retardant, graphite nanoplates (GNPs) as synergistic flame retardant/conductive filler, and acrylic resin as film forming agent, GNPs/MPP/acrylic coatings with outstanding flame retardancy, excellent heat resistance, and ideal electromagnetic interference (EMI) shielding were prepared by a simple physical blending method. The results showed that GNPs and MPP significantly improved the flame retardancy, heat resistance, and EMI shielding of acrylic coatings. By adding 20 wt% of GNPs and 20 wt% of MPP, the limiting oxygen index (LOI) value, heat resistance index (THRI), and EMI shielding effectiveness (SE) of GNPs/MPP/acrylic coating at the thickness of 40 μm reach 30% and 189.1 °C and 15 dB, respectively, which are better than those of pure acrylic coating (19%, 181.0 °C, and 0.1 dB). This intumescent fire-retardant coating with excellent flame retardancy, good heat resistance, and ideal EMI shielding performances has broad application prospects in the fields of construction, decoration, and electronics. Fire-retardant mechanism and combustion diagram of GNPs/MPP/acrylic resin coated wood