A multifunctional integrated coating reinforced with exfoliated boron nitride towards superior decorative, antibacterial, durable, and flame-retardant performances

Abstract

To solve the problems of traditional transparent fireproof coatings with a single-function nature and susceptibility to environmental aging, a novel functionalized exfoliated boron nitride (h-BN) with organophosphate (PPB) was synthesized and applied in an amino resin, preparing an integrated coating with decorative, fire-resistant, antibacterial, and weathering functions. The results indicate that the introduction of h-BN not only maintains the coating's high transparency but also enhances its hardness and adhesion capabilities. Furthermore, the presence of h-BN positively influences the flame retardance and smoke suppression of MBPPB coatings. Notably, when the mass ratio of PPB to h-BN is 98:2, the resulting MBPPB4 coating reduces the flame spread rate (FSR) by 45.7% and the smoke density rating by 62.6% compared to MBPPB0 coating without h-BN. Thermogravimetric analyses indicate that coatings containing h-BN exhibit superior char formation and thermal stability, where the MBPPB3 coating, with a PPB to h-BN ratio of 98.5:1.5, shows a 49.8% higher char yield at 800 °C than MBPPB0. The accelerated aging test demonstrates that the incorporation of h-BN also reduces the incidence of coatings blistering and cracking, thereby exhibiting outstanding weatherability. Additionally, h-BN significantly enhances the coating's antibacterial efficacy, with an E. coli inhibition rate of up to 99.0% for MBPPB3 coating.