- ▸ Addition-cure silicone base: Base polymer for platinum-cured elastomers.
- ▸ Silicone rubber: Forms crosslinked networks with hydride crosslinkers.
- ▸ Encapsulants and molding: Used in cured silicone potting and molding compounds.
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →Vinyl-terminated polydimethylsiloxane (CAS 68951-99-5) is a linear PDMS carrying reactive vinyl groups at the chain ends. It serves as the base polymer in addition-cure (hydrosilylation) silicone elastomer systems, reacting with hydride crosslinkers under platinum catalysis.
Regulatory & registration requirements
- TSCA (US):
- REACH (EU): Not determined from public registry
- EC number: 811-469-3
TSCA Inventory flag XU: a substance exempt from reporting under the Chemical Data Reporting Rule (40 CFR 711) (EPA flag legend).
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Solutions Using This Product
Process-solution guides on this site that specify this chemistry:
- Crosslinker Silanes for Moisture-Cure (RTV) Sealants (Coatings & Construction)
Frequently Asked Questions
What is vinyl-terminated PDMS used for?
Vinyl-terminated polydimethylsiloxane (CAS 68951-99-5) is the base polymer in addition-cure (hydrosilylation) silicone elastomer systems. It carries reactive vinyl groups at both chain ends that react with hydride crosslinkers under platinum catalysis to form crosslinked silicone rubber, used in encapsulants, potting, and molding compounds.
How does vinyl PDMS differ from standard (non-functional) PDMS?
Standard PDMS is a non-reactive silicone fluid; vinyl-terminated PDMS carries reactive vinyl groups at the chain ends. Those vinyl groups let it crosslink via hydrosilylation, so it functions as a curable elastomer base rather than an inert fluid.
What crosslinker and catalyst does vinyl PDMS require?
Vinyl-terminated PDMS cures by hydrosilylation with a hydride (Si-H) functional crosslinker in the presence of a platinum catalyst. The vinyl-to-hydride ratio and platinum loading govern cure rate and final network properties.
What viscosity grades of vinyl PDMS are available?
Vinyl-terminated PDMS is produced across a range of chain lengths and corresponding viscosities, which set the mechanical properties of the cured elastomer. Specific viscosity, vinyl content, and molecular weight are confirmed per lot on the Certificate of Analysis; request the CoA for the grade you need.
How is vinyl PDMS packaged and priced in bulk?
Vinyl-terminated PDMS ships under HS 3910.00 (silicones in primary forms) in pails, drums, and totes for elastomer manufacturers. Packaging, MOQ, and pricing depend on grade and volume; submit a bulk RFQ with your target viscosity and quantity.
What is the REACH and TSCA regulatory status of Vinyl-Terminated Polydimethylsiloxane (Vinyl PDMS)?
Vinyl-Terminated Polydimethylsiloxane (Vinyl PDMS) (CAS 68951-99-5) is listed as Active on the U.S. EPA TSCA Inventory; its REACH registration status is not determined from the public ECHA registry.