Silane-terminated polymers are important in moisture curing systems. Systems based on silane-terminated polyethers and polyurethanes are well established alongside the widespread silicone sealants and polyurethane adhesives. Silane-terminated systems have not only advantages of easy processing and high stability of the formulations, but also very good mechanical properties and adhesive strength that can be adjusted within a broad range. In contrast to conventional silylated polymers, GENIOSIL® STP-E 30 is characterized by its high reactivity toward moisture, a direct consequence of the structural proximity of the nitrogen atom to the silicon atom in the dimeth-oxy(methyl)silyl-methylcarbamate group (alpha-effect). Without the alpha-effect, the reactivity of a difunctional alkoxysilane is low and often too slow for most curing reactions in moisture-curing compositions, or needs to be accelerated by means of larger quantities of catalyst (usually organic tin compounds) or specially designed catalyst systems. Larger amounts of catalyst often have a negative effect on stability. Formulations with GENIOSIL® STP-E 30 are characterized by the following advantages:

• Simple compounding with conventional auxiliaries.
• Low viscosity in formulations
• High mechanical strength and high elongations
• Rapid curing.
• Tin-free catalysis.
• Broad adhesion profile

GENIOSIL® STP-E 30 is used as a reactive binder for adhesives and sealants, potting compounds and as additive in coatings. Curing takes place in the presence of water or atmospheric humidity. Depending on the formulation, either one-part or two-part systems can be prepared:

• Elastic adhesives in structural and automotive engineering.
• Assembly adhesives
• Overpaintable sealant for construction.
• Mold-making and potting compounds.

Information provided by Wacker Chemie AG.