Construction of decorative, antibacterial, anti-aging and fire-retardant integrative coatings for wood substrates with super protective performances

To prevent the coatings applied in historical buildings from aging failure due to environmental factors, integrative coatings with decorative, antibacterial, weather-resistant and flame-retardant properties are particularly important in practical applications. The nanocomposite flame retardants named CPPBs are obtained from the successful grafting of the phosphate esters to the surface of cerium oxide nanoparticles, which are physically blended with film-forming polymer to construct integrative coating named MCPPBs. The results show that adding nano-CeO2 greatly strengthens the mechanical property, fire protection performances, weather resistance, antibacterial activity of the integrative coatings, and maintains high light transmittance in the meantime. Especially, when the addition of nano-CeO2 in flame retardant is 0.5wt.%, the expansion ratio of the MCPPB3 coating increases to 65 and the char index reduces to 15.7cm3, concomitant with a high transparency of 80.3%. By combining FTIR, SEM and EDS analyses, it is found that the MCPPBs char containing nano-CeO2 is compact and dense. In the accelerated aging test, the back equilibrium temperature of the MCPPB3 coating at 900s is still less than 220°C and the surface morphology is complete after 6 aging cycles. In addition, the MCPPB3 coating exerts a negative effect on the growth of E. coli and S. aureus, and the antibacterial activities against E. coli and S. aureus are 92.8% and 96.2%.