Long‐Lasting Fire‐Resistant and Water‐Repellent Coating for Wood Protection

ABSTRACT Although the flame‐retardant coatings have been proven to be a good solution to protect wood products from fire, there is still a lack of industrially available and high‐performance coatings. Here, we proposed a wood coating that can endure more than 750 s fire burning without complex procedures to synthesize the flame retardants. A small modification to the traditional preparation methods results in a great improvement. Namely, the acid source, carbonizing source, and foaming source are premixed and encapsulated, and then are uniformly dispersed in coatings. The new coating has a performance of 17.8% better than that prepared by the conventional method in terms of fire‐resistant time, and the limited oxygen index of coated plywood is as high as 35.2%. The excellent fire‐resistance of this new coating is attributed to the quick decomposition of flame retardants in the early stage, which in turn quickly promotes the release of CO 2 and the formation of a char layer, based on the results of cone calorimetry and thermogravimetric‐infrared measurements. Moreover, the water contact angle of this fire‐resistant coating is improved to 151° after being decorated with hydrophobic SiO 2 nanoparticles. This strategy indicates that traditional flame retardants still have great potential through simple modifications to the preparation process.