Fluororubber (fluororubber) and fluorosilicone (fluorosilicone rubber) differ significantly in their chemical structure, performance characteristics, and application scenarios.

Chemical Structure: Fluorosilicone has a main chain composed of a silicon-oxygen bond (-Si-O-), with side chains containing fluorine groups such as trifluoropropyl. This combines the flexibility of silicone with the chemical resistance of fluorine. Fluoroelastomer, on the other hand, has a main chain composed of carbon chains, polymerized from fluorinated monomers such as vinylidene fluoride and hexafluoropropylene. It has a high fluorine content and a more rigid structure.

Temperature Resistance: Fluorosilicone has a long-term operating temperature range of -50°C to 200°C, and can withstand short-term temperatures of 250°C. Fluoroelastomer, on the other hand, has a long-term operating temperature range of -30°C to 250°C, with a short-term temperature resistance of up to 300°C, offering greater high-temperature stability.

Chemical Resistance: Fluorosilicone is more compatible with fuel oil, lubricating oil, and methanol gasoline; fluororubber is more resistant to strong acids (such as 98% concentrated sulfuric acid), strong bases, solvents, and aviation fuel.

Mechanical Properties: Fluorosilicone has lower tear strength and typically requires formulation optimization to enhance it; fluororubber offers strong tear resistance, higher hardness (65-90 Shore A), and better abrasion resistance.

Low-Temperature Adaptability: Fluorosilicone's brittle temperature can drop to -89°C, making it suitable for extremely cold environments; fluororubber readily becomes brittle around -30°C and has relatively weak low-temperature performance.

Applications: Fluorosilicone is primarily used in aviation fuel system seals (such as hydraulic bellows), automotive engine oil seals, methanol gasoline-resistant components, and medical anticoagulation catheters; fluororubber is suitable for highly corrosion-resistant seals in chemical equipment, high-temperature and high-pressure engine seals (such as O-rings), and radiation-resistant components in the nuclear industry.

Cost and Processing: Fluorosilicone raw material costs 30%-50% more than fluororubber. While it has excellent fluidity during processing, it's prone to bubbles. Fluororubber's high hardness requires a specialized vulcanization process, resulting in higher energy consumption.

Fluorosilicone is preferred for applications requiring low temperatures and high flexibility (such as medical or aviation seals). Fluororubber is more reliable in extremely high-temperature, highly corrosive environments (such as the chemical or nuclear industries). Considering both performance and cost, fluorosilicone excels in wide temperature ranges and biocompatibility, while fluororubber offers greater durability and chemical resistance.