Polycarbosilane is a high molecular weight organosilicon compound composed of carbon-silicon bonds and carbon-carbon bonds. Its production process can be divided into the following steps:
- Raw material preparation: The main raw materials of polycarbosilane are silane and alkyl compounds. Silane can be obtained by purification and hydrogenation of silicon ore, and alkyl compounds can be obtained through cracking products or petroleum by-products of petrochemical processes.
- Hydrogenation of silane: Silane undergoes hydrogenation reaction in the presence of hydrogen to break the silicon-hydrogen bonds in silane. This step can be carried out by different methods such as hot dip, electrolysis, and chemical phase deposition.
- Alkylation of silane: Alkylation is the reaction of hydrogenated silane with alkyl compounds to form polycarbosilane with carbon-silicon bonds and carbon-carbon bonds. Alkylation reaction can be carried out by catalyst catalysis, and commonly used catalysts include precious metal catalysts, transition metal catalysts, etc.
- Polymerization reaction: The product of polycarbosilane can undergo further polymerization reaction to increase the degree of polymerization and improve its performance. Common polymerization reactions include free radical combination, anionic polymerization, etc.
- Separation and purification: After the reaction, the product of polycarbosilane needs to be separated and purified. Common methods include membrane separation, solvent extraction, distillation, etc. These methods can obtain polycarbosilane with higher purity.
Processing and molding: Finally, polycarbosilane can be molded by extrusion, injection molding, calendering and other processing methods to prepare the required products.
