As a functional filler, silica has a wide range of applications in the field of flame retardants. The following is a detailed analysis of the use of silica as a flame retardant:
1. The basic concept of silica, also known as precipitated hydrated silica or fine silicic acid, is a white amorphous fine powder made by processing carbon black. It has the characteristics of light weight, high melting point (1750℃), good insulation, insoluble in water and acid but soluble in caustic soda and hydrofluoric acid. In addition, silica also has a high specific surface area and small particle size, which enable it to play an important role in flame retardants.
2. The flame retardant principle of silica The flame retardant principle of silica is mainly through its high specific surface area and small particle size, which absorbs and stabilizes the free radicals on the surface of the burning material when the material burns, forming a carbide layer to isolate the air and prevent further supply of oxygen, thereby curbing the spread of the fire source. In this process, silica can significantly improve the flame retardant properties of the material.
3. Application of Silica in Flame Retardant
Flame Retardant Rubber: Silica can be used to make flame retardant rubber, making rubber products less likely to burn in the event of a fire, thereby protecting people's lives and property.
Flame Retardant Plastics: Silica can also be used to make flame retardant plastics, such as PE, PP, etc. A higher amount of Silica can keep the integrity and mechanical properties of plastics after a fire, preventing burning substances from penetrating into the surrounding environment and causing greater fire accidents.
High Temperature Flame Retardant Coatings, Inks and Paper: Silica can also be used to make these flame retardant materials and improve their flame retardant properties.
4. Factors Affecting the Flame Retardant Effect of Silica
Addition Amount: The addition amount of Silica has a significant effect on the flame retardant effect. An appropriate amount of addition can improve the flame retardant properties, but an excessive amount may cause the material performance to deteriorate.
Material Type: The flame retardant effect of Silica in different materials is also different. Therefore, it is necessary to select the appropriate addition amount and ratio according to the specific material type.
Synergistic Flame Retardant: Silica is often used together with other flame retardants to show a significant synergistic flame retardant effect. For example, when used with silicon flame retardants, a denser heat-insulating and oxygen-insulating protective layer can be formed to improve flame retardant properties.
5. Precautions
Reasonable ratio and processing: When using white carbon black as a flame retardant, it is necessary to pay attention to reasonable ratios and processing methods to improve its flame retardant properties.
Safety: Although white carbon black itself is non-toxic and harmless, safety protection measures must still be taken during processing and use to avoid harm to the human body and the environment.
In summary, white carbon black, as a conventional flame retardant material, has broad application prospects and important value in the field of flame retardants. Through reasonable ratios and processing methods, its flame retardant properties can be fully utilized to provide strong protection for people's lives and property safety.