Types and Characteristics of Silicone Materials
I. Types of Silicone
Dimethyl Silicone
The earliest type of silicone to be commercially produced.
Maintains good elasticity within a temperature range of -60°C to 200°C.
Offers excellent aging resistance, electrical insulation, moisture resistance, shock resistance, and physiological inertness.
Primarily used for fabric coatings and in various extruded and calendered products for applications in the electromechanical, aerospace, automotive, and medical industries.
Methyl Vinyl Silicone
Adding a small amount of vinyl groups to the silicone molecular structure significantly improves curing and processing performance.
The most commonly used silicone, dominating global production.
Retains elasticity over a wide temperature range (-60°C to 260°C).
Features low compression set, good resistance to solvent swelling, stability under high-pressure steam, and excellent cold resistance.
Suitable for making thick products and widely applied in aviation, electrical, and medical fields.
Methyl Phenyl Vinyl Silicone
Derived by introducing methylphenyl siloxane or diphenyl siloxane units into the molecular chain of methyl vinyl silicone.
Features low compression set, a broad operating temperature range, oxidation resistance, weatherability, shock resistance, moisture resistance, and excellent electrical insulation.
Exceptional low-temperature resistance, ablation resistance, and radiation resistance.
The performance varies with phenyl content and is classified as low, medium, or high phenyl silicone.
Essential material for aerospace, advanced technology, and other critical sectors of the economy.
Fluorosilicone
Composed of γ-trifluoropropyl methyl polysiloxane.
Exhibits excellent chemical resistance, solvent resistance, and lubricating oil resistance, along with good cold resistance and thermal stability.
Also possesses superior flame resistance.
Used in aircraft, rockets, missiles, and space exploration for fuel and oil contact components such as hoses, gaskets, seals, and fuel tank liners. It can also be used to manufacture corrosion-resistant clothing, gloves, coatings, and adhesives.
Nitrile Silicone
Contains β-cyanoethyl or γ-cyanopropyl groups with strong polarity in the polymer side chains.
Excellent oil and detergent resistance and maintains elasticity within a range of -60°C to 180°C.
Used to produce oil-resistant rubber products for aerospace, automotive, and petroleum industries, and as high-performance environmental and fuel tank sealants in advanced aircraft.
Ethyl Silicone
Produced by introducing ethyl groups into the side chains of polysiloxanes to form diethyl silicone.
Exceptional cold resistance, superior to dimethyl silicone and standard methyl vinyl silicone.
Typically operates within a temperature range of -70°C to 200°C.
Silicone Nitride Rubber
Features outstanding thermal stability, maintaining performance without decomposition at 430°C to 480°C, and in some cases even above 500°C.
Hydrolysis resistance is poor, but polymers modified with cyclic disilazanes or silarylene-modified elastomers containing cyclic disilazanes demonstrate improved hydrolysis stability.
II. Characteristics of Silicone
High-Activity Adsorption: Silicone is a highly active adsorbent material with strong adsorption properties.
Chemical Stability: Insoluble in water and most solvents, non-toxic, odorless, and highly stable chemically. It reacts only with strong alkalis and hydrofluoric acid.
Thermal Stability: Silicone maintains stable performance over a wide temperature range. For example, dimethyl silicone retains good elasticity between -60°C and 200°C.
Mechanical Strength: Offers high mechanical strength, capable of withstanding considerable pressure and tension.
Modifiability: Silicone can be modified to create specialized materials to meet diverse functional requirements, such as luminescent, ion-releasing, or color-changing properties.