The process of converting silicone oil into silicone rubber is a complex process involving chemical synthesis and physical processing. Its core lies in the conversion of liquid silicone oil into a solid elastomer with a three-dimensional mesh structure through a specific chemical reaction.The following is a detailed analysis of this process：


1. Raw material selection and pretreatment
Basic silicone oil: Medium viscosity methyl silicone oil or vinyl silicone oil is usually used as the substrate. Its molecular structure is Si-O-Si as the main chain, and the side chain has active groups such as methyl or vinyl.
Crosslinking agent: Hydrogen-containing silicone oil is a key crosslinking agent. The Si-H bond in its molecule can react with the double bond in vinyl silicone oil to form a crosslinking point.
Catalyst: Platinum-based catalysts (such as chloroplatinic acid) are used to accelerate the silicon-hydrogen addition reaction and ensure that the crosslinking process is carried out efficiently.
Reinforcing filler: Fumed silica (nano-silica) is a commonly used reinforcing agent, which can significantly improve the mechanical strength and wear resistance of silicone rubber.
2. Core chemical reaction: silicon hydrogen addition and crosslinking
Under the action of a catalyst, hydrogen-containing silicone oil reacts with vinyl silicone oil to form a three-dimensional mesh structure.：


Reactive：
Si-H + CH₂=CH-Si = SiCH2CH2Si
The reaction combines the Si-H bond with the double bond of vinyl to form a stable Si-C bond, which connects the linear silicone oil molecular chains to each other to form a cross-linked network.
3. Processing technology: the transition from liquid to solid state
Mixing: Add silicone oil, crosslinking agent, catalyst, reinforcing filler and other additives (such as structural control agent and anti-aging agent) to the mixer proportionally, and mix evenly at high temperature to form a plastic compound rubber.
Molding: By calendering, extrusion or injection molding, the mixed rubber is processed into the desired shape (such as sheet, pipe, seal).
Vulcanization: The molded product is placed in a high temperature (120-200℃) environment, and the catalyst initiates a silicon-hydrogen addition reaction to change the rubber compound from a viscous liquid state to a highly elastic solid state.The vulcanization time is adjusted according to the thickness of the product and the process requirements, usually 10-30 minutes.
Post-treatment: Some products need to be secondary vulcanized (200-250℃) to further eliminate residual stress and improve performance stability.
4. Performance optimization and modification
By adjusting the raw material ratio and process parameters, the performance of silicone rubber can be customized：


High temperature resistance: Phenyl silicone oil or boron-containing additives are introduced to improve the stability of silicone rubber in high temperature environments.
Self-repairing: Hydrogen-containing silicone oil and vinyl silicone oil are encapsulated in microcapsules. When the material is damaged, the microcapsules break and release the crosslinking agent to achieve automatic repair.
Medical grade modification: strictly control the purity of raw materials and the processing environment to ensure that silicone rubber is non-toxic, biocompatible, and suitable for medical device manufacturing.