Modifier OH 655 Polydimethylsiloxane Hanse Chemie Plasticizers Silicones (Si) SEALANT Reactive plasticizer The Modifier OH products consist mostly of monofunctional polydimethysiloxane, which has both a non-reactive and a reactive chain end. This makes them suitable for producing soft silicone sealants which must not release any more than the bare minimum plasticiser components. Silicone formulations using Modifier OH 655 can be produced like other familiar polymer/plasticiser mixtures. Crosslinking of the reactive chain ends of these modifiers can be achieved with the help of the familiar condensation curing crosslinkers. Monofunctional polydimethylsiloxane. Used as reactive plasticizer for producing soft silicone sealants.