Dynasylan® VTEO is a bifunctional organosilane possessing a reactive vinyl group and a hydrolyzable inorganic triethoxysilyl group.
Scope of Application
1. Moisture curing of polymers Dynasylan® VTEO is suitable for the preparation of moisture-curing polymers, e.g. polethylene. The characteristic feature of this process is peroxide-initiated grafting of the vinylsilane to the polymer during extrusion. After grafting, the polymer can still be processed as a thermoplast. Only upon treatment with moisture (in an 80-100°C waterbath, steambath, or even at ambient conditions), are the polymer chains linked together via the formation of siloxane bonds, thereby forming a crosslinked polymer. This reaction can be accelerated by using a catalyst. Silane crosslinked polyethylene is widely used as cable isolation, and sheathing mainly in low voltage applications as well as for hot water/sanitary pipes and underfloor heating. Heat resistance is the main reason for the crosslinking of polymers for cable applications, but crosslinking can also improve the following properties: tear- and crack resistance, chemical resistance, abrasion resistance, memory effect. Dynasylan® VTEO may also be used as a comonomer for the preparation of different polymers such as polyethylene or acrylics. Those polymers show an improved adhesion to inorganic surfaces and they can also be crosslinked with moisture as described above. 2. Adhesion promotion and surface modification Because of its ability to react with inorganic fillers as well as with organic polymers (activated by e.g. peroxides or radiation), Dynasylan® VTEO acts as an adhesion promoter for various mineral-filled polymers, improving mechanical and electrical properties especially after exposure to moisture. Once bonded to an inorganic filler, Dynasylan® VTEO hydrophobizes the filler surface, improving the compatibility of fillers with polymers, leading to a better dispersibility, reduced melt viscosity and easier processing of filled plastics. Surface coating of glass, metal or ceramics with Dynasylan® VTEO will improve not just adhesion, especially of acrylic systems, but also corrosion or scratch resistance. 3. Dynasylan® VTEO as co-monomer for polymer dispersions Polymer dispersions (e.g. styrene acrylics), modified with Dynasylan® VTEO show improved adhesion strenght in wet conditions and wet scrub resistance.