SilanKopplungsagenten

SilanKopplungsagenten, also known as organosilane coupling agents, are a class of organosilane compounds used to enhance adhesion between inorganic substrates (such as glass, metal oxides, and silicates) and organic polymers (including resins, elastomers, and coatings). They contain a hydrolyzable alkoxy or methoxy group that can react with surface hydroxyls of the inorganic material, while a functional organic group (e.g., amino, epoxy, methacrylate) provides compatibility with the polymer matrix.

The typical coupling reaction involves hydrolysis of the alkoxy groups to form silanol groups, followed by condensation with surface hydroxyls to form stable Si–O–Si bonds. Simultaneously, the organic functional group undergoes polymerization or crosslinking within the organic phase. This dual reactivity creates a molecular bridge, improving interfacial bonding, mechanical strength, and environmental resistance of composites.

SilanKopplungsagenten are widely used in industries such as automotive, construction, aerospace, and electronics. Applications include adhesive bonding of glass to plastic, reinforcing fiber–reinforced composites, enhancing paint adhesion to stone or metal, and modifying surface wettability. They also serve as primers in glass-fiber laminates and as agents for improving corrosion resistance on metal surfaces.

Common examples are γ‑(3‑aminopropyl)triethoxysilane (APS), γ‑(methacryloxypropyl)trimethoxysilane (MPS), and 3‑(triethoxysilyl)propyl isocyanate (TESPIC). Industrial grades differ in purity, functionality, and solubility to meet specific process requirements. Environmental concerns focus on the use of solvents and potential toxicity of silicon oxide byproducts; hence, newer formulations aim for lower VOC content and safer handling.