GENIOSIL® GF 91
N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane, high purity
Thanks to the specific reactivity of the 2-aminoethyl-aminopropyl structure, using GENIOSIL® GF 91 as an adhesion promoter in glass-fiber reinforced or fillermodified plastics reduces the filler's sedimentation tendency and improves dispersibility and numerous mechanical properties (e.g. flexural strength, tensile strength, modulus of elasticity) of these composites. The use of GENIOSIL® GF 91 in these materials also results in a markedly improved resistance to water, vapor and corrosion. Electrical properties, such as volume resistivity and the dielectric constant, are also positively influenced.
GENIOSIL® GF 91 is an alkoxysilane with an amino-functional group. t´s a clear, colorless to light yellow liquid with a characteristic amine odor. Compared to GENIOSIL® GF 9, it is additionally purified by distillation. As a result, it offers extremely high purity and, above all, a very low chloride content. Due to the nature of its amino group, GENIOSIL® GF 91 reacts as a strong base. The silane hydrolyzes autocatalytically in the presence of moisture (methanol is released) to form silanols, which can then react with themselves to produce siloxanes or can bind to inorganic substrates. As a typical amine, GENIOSIL® GF 91 can also interact with numerous organic polymers and thus function as a molecular bridge between organic and inorganic substrates.
1. General processing information
GENIOSIL® GF 91 is highly miscible with organic sol-vents, such as ethers and hydrocarbons.
Mixing with ketones results in imine formation, while mixing with alcohols other than methanol leads to an autocatalytic exchange of alkoxy groups until the system reaches thermodynamic equilibrium.
GENIOSIL® GF 91 demonstrates typical amine behavior when exposed to acids, epoxides or isocyanates. GENIOSIL® GF 91 is highly soluble in neutral water.
Caution: due to the enthalpy of solution, mixing GENIOSIL® GF 91 with water is exothermic. It is recommended that GENIOSIL® GF 91 is added to water, not vice versa, while stirring.
A 2 wt % solution of GENIOSIL® GF 91 in water has a pH of 10 -11 and remains stable for several weeks. Due to the reactive nature of GENIOSIL® GF 91, contact with moisture must be avoided during prevent undesired hydrolysis.
Fillers are treated either with pure GENIOSIL® GF 91 or a solution thereof. It may be necessary to pretreat the substrate with water.
The modified filler is preferably bonded to the organic material, e.g. an epoxy resin, by mixing it with a standard amine curing agent.
In an alternative procedure referred to as "blending", GENIOSIL® GF 91 is added directly to the polymer - either before the organic materials is compounded with the filler or at the same time.
A prerequisite for the blending process is that GENIOSIL® GF 91 and the polymer are compatible and that the resin and GENIOSIL® GF 91 do not react prematurely.
Used as a primer, GENIOSIL® GF 91 is applied as an aqueous or organic solution to an inorganic substrate (e.g. metal or glass surfaces). Once GENIOSIL® GF 91 has dried and bonded to the surface, an organic coating may be applied using a standard technique (e.g. spraying or knife coating).
GENIOSIL® GF 91 is mainly used as a surface modifier for glass fibers, glass-fiber fabrics, fillers (e.g. glass or mineral wool, mica, talc, wollastonite, kaolin, christobalite, metal oxides) and pigments used in various plastics, including epoxy resins, polyamides, polyacrylates, polyurethanes, ethylene/vinyl acetate copolymers and many others.
Other important applications include its uses as an adhesion promoter in polysulfides and phenolic resins for abrasives and insulating materials and as a primer for sealants, adhesives and coatings.