Organofunctional silane compounds

Organofunctional silanes are used to promote polymer-to-filler bonding with clay or siHca fillers. Vinyl silanes are used in peroxide-cured wire insulation to promote stronger bonding with calcined clay fillers. Mercapto silanes are used to treat kaolin clay in sulfur-cured compounds. 

The approach to obtaining adhesion is to use an intermediate chemical compound between the glass and the matrix. The bridging agents used are organofunctional silanes. These materials bond to the glass surface as well as to the matrix. 

Organofunctional silanes with hydroxy-, epoxy-, acryl-, ester- and carboxy-functions are produced industrially. They are in particular utilized as additives for modification of polymers and for functionalizing silicones for different application sectors. Most of these compounds are manufactured by the addition of appropriately functionalized alkenyl-compounds. 

Combining silanes with silica led to high-performing silica-filled rubber compounds. Organofunctional silanes with polysulfane groups such as bis-(3-(triethoxysilyl)propyl)tetrasulfane (TESPT) and bis-(3-(triethoxysilyl)propyl)disulfane (TESPD) (Fig. 12) are utilized to improve dispersability of silica in the rubber matrix. 

Reactive silanes were tested on glass with the same rubbers (Table 1), as well as with natural, nitrile. Neoprene, and Hypalon compounds (Table 2). In addition to simple mono-organofunctional silanes these tests included polyfunctional silanes ... 

Mechanical Properties of Natural Rubber Compounds (Clay fillers treated with organofunctional silanes)... 

The organofunctional portion bonds with the resin in the adhesive or the organic medium, and the silane portion bonds to the inorganic or substrate surface. Silane coupling agents are commonly used between the adhesive and the adherend, between resin matrix and reinforcing fibers in composites, and between resin matrix and mineral fillers in compounds. The resulting interface provides... 

Organofunctional polysiloxanes with silanol groups can be cross-linked at low temperatures with tetrabutyl titanium, methyl triacetoxy-silane, and similar compounds and are thus used as cold vulcanization materials. In contrast, hot vulcanizable silicones possess one vinyl group in about 500-1000 monomeric units and can be cross-linked with peroxides. All silicon rubbers are filled with highly dispersed silica since the unfilled rubber is practically a useless elastomer. 

The term silsesquioxanes refers to all the structures with the empirical formula (RSiOi.sln, where R is a hydrogen or any alkyl, aryl, alkylene, arylene, or organofunctional derivative. Such compounds are synthesized by hydrolytic condensation of trifunctional silanes. The trifunctional nature of the silsesquioxane moieties allows the formation of a variety of structures, ranging from oligomeric cages to ordered ladder-like structure to three-dimensional network structure to functionalized silicates (called spherosilicates). 

---