Fluorosilicone is a specialized synthetic rubber formed by introducing fluorine-containing groups (such as trifluoropropyl) into the silicone rubber backbone. It combines the heat resistance of silicone rubber with the oil resistance of fluororubber, making it valuable for applications in extreme environments. Its core knowledge and characteristics are as follows:

I. Basic Definition and Structure
Chemical Nature: It is based on γ-trifluoropropylmethylpolysiloxane (codenamed FVMQ), with a main chain consisting of silane-oxygen bonds (-Si-O-) and side chains containing trifluoropropyl groups (-CH₂CH₂CF₃).
Synthesis Principle: It is prepared by a hydrolysis-polycondensation method, using methyltrifluoropropylcyclotrisiloxane and tetramethyldivinyldisiloxane as common raw materials.

II. Core Properties
Media Resistance: It is resistant to fuel, motor oil, aromatic hydrocarbons, and chlorinated hydrocarbon solvents. Its chemical resistance is superior to that of ordinary silicone rubber and even exceeds that of some fluororubbers.
It remains stable in a methanol-gasoline mixture (85% gasoline + 15% methanol). Temperature Resistance
Long-term operating temperature: -68°C to 232°C, short-term resistance to 250°C; low-temperature brittleness reaches -89°C, and low-temperature elasticity surpasses that of fluororubber.
Addition of heat stabilizers such as iron and titanium is required to enhance high-temperature durability.
Physical Properties
Low compression set (compression rate ≤ 22% at 177°C for 22 hours), high resilience and insulation properties.
Wide hardness range (Shore A 30-80 ± 3), tensile strength approximately 10 MPa, and tear strength 45 kN/m.