What are the ingredients of flame retardant silicone?

What are the ingredients of flame retardant silicone?
Basic silicone: Basic silicone is usually silicone rubber, which is mainly divided into room temperature vulcanized silicone rubber (RTV) and high temperature vulcanized silicone rubber (HTV). Room temperature vulcanized silicone rubber can undergo vulcanization reaction at room temperature to form an elastomer. It is easy to use and is often used in some on-site construction or the preparation of small products; high temperature vulcanized silicone rubber needs to be vulcanized at a higher temperature (generally 150℃-200℃). The vulcanized rubber has high strength and excellent physical properties and is suitable for large-scale industrial production.
Flame retardant:
Halogen-containing flame retardant: Mainly brominated flame retardants, such as decabromodiphenylethane, tetrabromobisphenol A, etc. Their flame retardant mechanism is to release hydrogen halides during combustion. These gases can capture free radicals generated during the combustion process and interrupt the chain reaction of combustion, thereby achieving a flame retardant effect. However, since halogen-containing flame retardants may produce toxic and harmful gases during combustion, their use is subject to certain restrictions.
Halogen-free flame retardants: Common metal hydroxides include aluminum hydroxide and magnesium hydroxide. They decompose when heated, absorbing a large amount of heat and lowering the temperature of the material surface. At the same time, the water vapor produced by the decomposition can dilute the oxygen concentration and play a flame retardant role. In addition, phosphorus flame retardants such as red phosphorus and phosphate esters are also commonly used. Their flame retardant mechanism includes forming a carbon layer on the combustion surface, isolating the transfer of oxygen and heat, and capturing free radicals in the gas phase.
Reinforcement agent: In order to improve the strength, hardness and wear resistance of flame retardant silicone, reinforcing agents are usually added. The most commonly used reinforcing agent is fumed silica (silicon dioxide), which can form hydrogen bonds with silicone rubber molecules to enhance the mechanical properties of silicone. Precipitated silica can also be used as a reinforcing agent, but its reinforcing effect is slightly worse than that of fumed silica.
Plasticizer: The role of plasticizer is to reduce the hardness and viscosity of silicone and improve its processing performance and flexibility. Commonly used plasticizers include methyl silicone oil, etc. By adding suitable plasticizers, flame retardant silicone can be made easier to mix, mold and other processing operations, while meeting the requirements of silicone flexibility in different application scenarios.
Vulcanizer: The function of the vulcanizer is to cause cross-linking reaction between silicone rubber molecules to form a three-dimensional network structure, thereby transforming silicone from a viscous fluid into an elastic solid. For room temperature vulcanized silicone rubber, commonly used vulcanizers include platinum-containing catalysts, peroxides, etc.; high temperature vulcanized silicone rubber usually uses organic peroxides as vulcanizers.
Other additives: According to specific performance requirements, some other additives may also be added, such as antioxidants to prevent silicone from aging due to oxidation, ultraviolet rays, etc. during long-term use; coupling agents to improve the interface bonding performance between silicone and fillers; masterbatches to give silicone different colors, etc.