Thread Content
Fireproof coating is a special type of coating that reduces the flammability of the surface of the substrate it is applied to, prevents the rapid spread of fire, and increases the fire resistance rating of that substrate. Fireproof coatings can be classified into two categories based on their flame-retardant mechanisms. One category is intumescent fireproof coatings, which soften, melt, and expand when exposed to fire, forming a sponge-like or honeycomb-shaped carbonized layer ； Another type is non-expanding fireproof coatings, which absorb a large amount of heat when exposed to fire, preventing the temperature from rising, and form a protective layer on the surface of the object that blocks oxygen. The two-dimensional sheet structure of graphene, on the one hand, forms a dense insulating layer within the coating that provides flame-retardant effects; on the other hand, it can cross-link with resins to create a protective layer that acts as a barrier to air. Bai Huiwen added the modified graphene oxide to silicone resin and studied the effect of graphene oxide on the heat resistance of the silicone resin. The results show that the addition of graphene oxide improved the heat resistance of the silicone resin. The main reason for this is that the graphene oxide dispersed in the silicone resin coats the outer surface of its network structure; the graphene oxide sheets act as a protective layer, reducing contact between oxygen and other reactive molecules and the silicone resin. At the same time, the graphene oxide sheets hinder the movement of the chain segments in the silicone resin, thereby improving its heat resistance. Expanded graphite possesses excellent flame-retardant and smoke-suppressing properties, and can be used as a flame retardant in coatings. As a crystal with a thickness of a single carbon atom, graphene makes up expanded graphite; it possesses a high specific surface area and excellent heat resistance, which is why it can also be used in expanded fire-retardant coatings. Li Hongfei et al. added graphene oxide to acrylic intumescent flame-retardant coatings and studied their flame-retardant properties and smoke-suppression effects. The results show that adding an appropriate amount of graphene oxide to the flame-retardant system induces the alignment of polymer molecular chains and the formation of a \"skeletal\" structure when the coating expands due to heat, thereby significantly strengthening the carbon layer and exerting a flame-retardant effect. The best effect is achieved when the addition amount is 0.025 parts, resulting in a 42% increase in flame resistance time. At the same time, graphene oxide possesses gas barrier properties, which effectively prevent the leakage of solid particulates formed during combustion, and it also offers a very significant smoke-suppressing effect.