Liquid Silicone Manufacturing Process

For example, hydroxyl-terminated polydimethylsiloxane with a viscosity of 0.07~50 Pa·s/25°C, using methylvinylbispyrrolidone silane as a chain extender, using organic peroxides such as dibenzoyl peroxide , 25-dimethyl 5-di-tert-butyl peroxyhexane as vulcanizing agent, this kind of rubber compound has good fluidity and low viscosity, and chain growth reaction occurs at the same time during its vulcanization process, so high molecular weight elastomer can be obtained. , has good physical and mechanical properties. The chain extender methylvinylbispyrrolidone silane can be obtained by the reaction of pyrrolidone and methylvinyldichlorosilane in the presence of triethylamine. The product is easily hydrolyzed, so it needs to be stored in a dry and airtight container. The pyrrolidone of this compound is The group can react slowly with the terminal hydroxyl groups in the polydimethylsiloxane at room temperature, and the reaction speed increases with the increase of temperature. Theoretically, this reaction can be continued until an infinite molecular weight is obtained. The vinyl group in methylvinylpyrrolidone silane can also be used as the activation point of the vulcanization reaction, which can promote the crosslinking of polydimethylsiloxane and generate high molecular weight elastomer. Since the reaction between the pyrrolidone group and the hydroxyl group is very slow at room temperature, the compound after adding each component and mixing has a long pot life. The viscosity of the compound is basically unchanged within 1 hour, but it still maintains good fluidity. Can be injected into tiny pores. The mixed rubber can be vulcanized into an elastomer by heating at 150°C for 10 minutes.