How do elastomer flame retardants prevent the spread of fire?

Elastomeric flame retardants prevent the spread of fire primarily through a combination of mechanisms. The following is its main working mechanism:

Physical isolation: Flame retardants can form a protective film on the surface of the material, such as a ceramic-like or glass-like oxide layer, covering the material and isolating the burning material from oxygen, thus preventing the further spread of the flame. This insulation also reduces the conduction of heat to unburned areas, slowing the spread of fire.

Chemical effects: Flame retardants undergo chemical reactions during the combustion process, and these reactions help inhibit the spread of flames. For example, some flame retardants decompose at high temperatures to release water vapor or inert gases, which can dilute the oxygen in the combustion products, thereby reducing the temperature and burning speed of the flame. In addition, flame retardants may absorb heat and lower the temperature of the burning area, further slowing down the combustion reaction.

Vapor phase suppression: Flame retardants can interfere with the oxygen supply around the flame and reduce the oxygen concentration in the combustion area, thus slowing down the combustion reaction rate. This gas-phase suppression helps inhibit flame expansion and extension.

Free radical capture: Some flame retardants can capture free radicals and prevent the combustion chain reaction from proceeding. The combustion chain reaction is a key process for continuous flame combustion. Flame retardants can effectively inhibit the sustainability of combustion by interfering with this process.

Elastomer flame retardants work together through multiple mechanisms such as physical isolation, chemical action, gas phase inhibition, and free radical capture to effectively prevent the spread of fire and improve material safety. However, flame retardants are not a panacea, and when using elastomer materials containing flame retardants, relevant safety regulations and precautions still need to be followed to minimize the risk of fire.