Modifier 705 and Modifier 715 are SiH-terminated polydimethyl siloxanes which are used as plasticizers in addition-curing silicones. Due to their difunctional structure, these products do not react by cross-linking, but by extending the chains of vinyl-terminated silicone polymers (Polymer VS). Use of the modifiers reduces the crosslinking density and therefore the elastomer hardness. Application: Use of the modifiers allows obtaining products with a low Shore hardness, even when using low-viscosity vinyl polymers. These modifiers are therefore used in formulations that have a low viscosity prior to crosslinking and should have low Shore hardness after crosslinking. Another important modifier application is the formulation of silicone gels. When working with two-component silicone formulations, it must be ensured that Pt-catalyst (e. g. Catalyst 500 series) and modifier are kept strictly apart. Information provided by Evonik |