Silanes

Alkyl Silane - Conventional Surface Bonding Aliphatic, fluorinated aliphatic or substituted aromatic hydrocarbon substituents are the hydrophobic entities which enable silanes to induce surface hydrophobicity. The organic substitution of the silane must be non-polar. The hydrophobic effect of the organic substitution can be related to the free energy of transfer of hydrocarbon molecules from an aqueous phase to a homogeneous hydrocarbon phase. A successful hydrophobic coating must eliminate or mitigate hydrogen bonding and shield polar surfaces from interaction with water by creating a non-polar interphase. Although silane and silicone derived coatings are in general the most hydrophobic, they maintain a high degree of permeability to water vapor. This allows coatings to breathe and reduce deterioration at the coating interface associated with entrapped water. Since ions are not transported through non-polar silane and silicone coatings, they offer protection to composite structures ranging from pigmented coatings to rebar reinforced concrete. A selection guide for hydrophobic silanes can be found on pages 22-31 of the Hydrophobicity, Hydrophilicity and Silane Surface Modification brochure. Dodecylmethyldichlorosilane; Dichlorododecylmethylsilane; Methyldodecyldichlorosilane

Olefin Functional Trialkoxy Silane Silane coupling agents have the ability to form a durable bond between organic and inorganic materials to generate desired heterogeneous environments or to incorporate the bulk properties of different phases into a uniform composite structure. The general formula has two classes of functionality. The hydrolyzable group forms stable condensation products with siliceous surfaces and other oxides such as those of aluminum, zirconium, tin, titanium, and nickel. The organofunctional group alters the wetting or adhesion characteristics of the substrate, utilizes the substrate to catalyze chemical transformations at the heterogeneous interface, orders the interfacial region, or modifies its partition characteristics, and significantly effects the covalent bond between organic and inorganic materials. Alkenylsilane Cross-Coupling Agent The cross-coupling reaction is a highly useful methodology for the formation of carbon-carbon bonds. It involves two reagents, with one typically being a suitable organometallic reagent - the nucleophile - and the other a suitable organic substrate, normally an unsaturated halide, tosylate or similar - the electrophile. Vinyltriethoxysilane; Triethoxyvinylsilane; TEVS; VTES; Ethenyltriethoxysilane; Triethoxysilylethylene; Triethoxy(vinyl)silane ΔHvap: 6.8 kcal/molΔHform: -463.5 kcal/molDipole moment: 1.69 debyeSpecific wetting surface area: 412 m2/gCopolymerization parameters- e,Q: -0.42, 0.028γc of treated surfaces: 25 mN/mVapor pressure, 20 °C: 5 mmSpecific heat: 0.25 cal/g/°Relative hydrolysis rate versus SIV9220.0, vinyltrimethoxysilane; 0.05Forms copolymers with ethylene for moisture induced coupling of polyethyleneCouples fillers or fiberglass to resinsSee VEE-005 for polymeric versionReacts with enamines to give (E)-β:-silylenamines, which cross-couple with aryl iodides to give β-aryl enaminesEmployed as a coupling agent, adhesion promoter, and crosslinking agentUsed in microparticle surface modification for fillersCompatible with sulfur and peroxide cured rubber, polyester, polyolefin, styrene, and acrylic based materialsFor vinylationsAvailable as an oligomeric hydrolysate, SIV9112.2Extensive review of silicon based cross-coupling agents: Denmark, S. E. et al. "Organic Reactions, Volume 75" Denmark, S. E. ed., John Wiley and Sons, 233, 2011

dimethoxysilylmethylpropyl modified (polyethylenimine) Polyamino hydrophilic dialkoxysilanePrimer for brassViscosity: 100-200 cSt~20% of nitrogens substituted50% in isopropanol

Trialkylsilyl Blocking Agent Used as a protecting group for reactive hydrogens in alcohols, amines, thiols, and carboxylic acids. Organosilanes are hydrogen-like, can be introduced in high yield, and can be removed under selective conditions. They are stable over a wide range of reaction conditions and can be removed in the presence of other functional groups, including other protecting groups. The tolerance of silylated alcohols to chemical transformations summary is presented in Table 1 of the Silicon-Based Blocking Agents brochure. tert-Butyldimethylsilyltrifluoromethanesulfonate; TBS-OTf; t-Butyldimethylsilyltriflate More reactive than SIB1935.0Converts acetates to TBS ethersUsed for the protection of alcohols, amines, thiols, lactams, and carboxylic acidsClean NMR characteristics of protecting groupFacile removal with flouride ion sourcesSummary of selective deprotection conditions is provided in Table 7 through Table 20 of the Silicon-Based Blocking Agents brochure

3-Aminopropylsilanetriol, 3-trihydroxysilylpropylamine; 22-25% in water Monoamino functional water-borne silaneMainly oligomers; monomeric at concentrations <5%pH: 10.0-10.5No VOC primary amine coupling agentInternal hydrogen bonding stabilizes solutionSee WSA-7011 for greater hydrolytic stability