Tetramethyltetravinylcyclotetrasiloxane

Tetramethyltetravinylcyclotetrasiloxane (CAS 2554-06-5, EC 219-863-1) is a cyclic siloxane monomer carrying four vinyl functional groups, commercially known as PS 925. It belongs to the silicone chemistry family and carries no assigned E-code. Its molecular formula is C12H24O4Si4.

In platinum-catalyzed addition-cure silicone systems, the vinyl groups react with Si-H functional crosslinkers to form three-dimensional polymer networks, controlling elastomer hardness and crosslink density. It also serves as a reactive modifier in electronics encapsulants and aerospace-grade silicone elastomers, where precise network architecture determines dielectric and thermal performance.

This material is supplied as a colorless liquid and is registered under REACH. It is handled under standard industrial chemical protocols applicable to reactive siloxane monomers. Procurement teams should confirm lot-specific purity documentation and SDS compliance with EU GHS requirements. HS code 29319090 applies for import classification within the European customs area.