What Is Vinyl-Fluorosilicone Oil?
Vinyl-fluorosilicone oil is a low-molecular-weight fluorosilicone polymer containing vinyl functional groups along the molecular chain. It belongs to the family of reactive liquid additives for addition-cure fluorosilicone rubber systems.Unlike ordinary fluorosilicone oils, it carries vinyl groups that can participate in platinum-catalyzed addition reactions, so it not only provides typical fluorosilicone properties such as oil resistance, solvent resistance, fuel resistance and low surface tension, but also becomes part of the crosslinked network after curing.
In addition-cure liquid fluorosilicone rubber, fluorosilicone potting compounds, fluorosilicone sealants and fluorosilicone elastomer formulations, vinyl-fluorosilicone oil is commonly used as a reactive diluent, chain extender, viscosity regulator and crosslink-density modifier.Compared with inert diluents, it does not migrate or exude after vulcanization, but integrates into the crosslinked network, helping to improve processing flow, reduce viscosity, adjust hardness and elasticity, and maintain oil and solvent resistance.
The product typically appears as a colorless to light yellow transparent liquid, available in a wide viscosity range. It can be customized by vinyl content and viscosity grade, and should be stored sealed, protected from light and moisture, and kept away from platinum catalyst inhibitors.
Key Technical Indicators
Vinyl Content
Vinyl content is the core parameter determining the reactivity of vinyl-fluorosilicone oil. Higher vinyl content provides stronger participation in platinum-catalyzed addition reactions, with greater influence on crosslink density, hardness and tensile properties.Different grades may have vinyl contents ranging from about 0.5% to 6%, depending on the downstream formulation requirements.
Viscosity Range
Viscosity can range from tens to thousands of mPa·s. Low-viscosity grades are more suitable as reactive diluents for reducing the viscosity of potting compounds, sealants and liquid fluorosilicone rubber systems; medium- to high-viscosity grades can be used for chain extension, flexibility adjustment and processing improvement.
Fluorine Content and Oil Resistance
The trifluoropropyl structure provides good resistance to oils, fuels, lubricants and non-polar solvents. Compared with ordinary vinyl silicone oil, vinyl-fluorosilicone oil is more stable in fuel, oil and solvent environments, making it suitable for automotive fuel systems, aerospace sealing and oil-resistant potting applications.
Service Temperature Range
Vinyl-fluorosilicone oil typically remains stable from approximately -50°C to +200°C, with some grades able to withstand higher temperatures for short periods. After curing, its temperature resistance depends on the overall fluorosilicone formulation, but it generally outperforms many ordinary silicone rubber systems in oil-exposed environments.
Compatibility
It shows good compatibility with hydrogen-containing fluorosilicone oil, vinyl fluorosilicone rubber base polymers, addition-cure liquid fluorosilicone rubber and platinum catalyst systems. At proper ratios, it can improve filler dispersion, reduce viscosity and adjust post-cure elastomer properties.
Storage Stability
The product should be stored in sealed containers, away from moisture, acids, alkalis and platinum inhibitors such as sulfur-, amine-, tin- or phosphorus-containing compounds. When uncontaminated, storage stability is good, with typical shelf life of 6-12 months, subject to the supplier's technical data.
Main Performance Features
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Participates in platinum cure: vinyl groups enable addition reactions and integration into the crosslinked network.
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Reactive dilution: reduces viscosity without migration issues associated with inert diluents.
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Oil and fuel resistance: trifluoropropyl groups enhance resistance to fuels, oils and non-polar solvents.
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Crosslink-density control: adjusts hardness, tensile strength and elasticity through vinyl content and dosage.
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Improved processability: supports filler dispersion, deaeration, potting, coating and injection molding.
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Low surface tension: improves wetting, leveling and substrate adhesion performance.
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Customizable viscosity and activity: can be tailored for addition-cure fluorosilicone rubber, potting compounds and sealants.
Typical Application Scenarios
Addition-Cure Liquid Fluorosilicone Rubber
In two-component addition-cure liquid fluorosilicone rubber, vinyl-fluorosilicone oil acts as a reactive diluent and chain extender, reducing A/B component viscosity and improving mixing, deaeration and injection molding while maintaining oil and solvent resistance.
Fluorosilicone Potting Compounds
Used in potting formulations for electronic components, sensors, wire harness connectors, automotive control modules and aerospace electronics, helping reduce viscosity, improve leveling and fill complex structures.
Fluorosilicone Sealants and Coatings
In oil-resistant sealants, fuel-system sealing coatings and solvent-resistant protective coatings, it adjusts viscosity and post-cure elasticity, and improves wetting on metal, plastic and elastomer substrates.
Automotive Oil-Resistant Elastomers
Applied in fuel line seals, turbocharger hose seals, engine-area oil-resistant gaskets and sensor encapsulation materials, improving formulation performance against fuels, lubricants and high temperatures.
Aerospace Fluorosilicone Elastomers
Suitable for aerospace fuel system seals, hydraulic system protective coatings and solvent-resistant elastomer components, meeting both wide-temperature and media-resistance requirements.
Fluorosilicone Elastomer Modification
Used in platinum-cure fluorosilicone rubber, fluorosilicone compounded rubber modification, hardness adjustment and flow improvement as a functional additive.
Selection and Usage Recommendations
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Confirm curing system compatibility: suitable only for platinum-catalyzed addition-cure systems, not for peroxide or condensation-cure systems.
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Select viscosity by processing needs: choose low viscosity for significant viscosity reduction; choose medium to high viscosity for chain extension and elasticity adjustment.
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Adjust dosage by crosslink density: vinyl content and dosage affect hardness, tensile strength and elongation; small-scale trials are recommended.
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Avoid platinum inhibitor contamination: keep away from sulfur-, amine-, tin- and phosphorus-containing compounds to prevent inhibited cure or tacky surfaces.
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Use with hydrogen-containing fluorosilicone oil: in addition-cure systems, vinyl-fluorosilicone oil usually needs to be combined with hydrogen-containing fluorosilicone oil or hydrogen-containing crosslinkers.
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Key points for overseas customers: highlight vinyl reactivity, oil/fuel resistance, non-migrating reactive dilution, potting flow improvement and customizable vinyl content/viscosity to support sampling, formulation trials and bulk orders.
Vinyl Fluorosilicone Oil IOTA-25V
