Silane Modified Polymers (SMP)

Properties and Applications

Silyl-terminated polethers, also known as silane modified polymers (SMP) or MS-polymers, are innovative and environmentally friendly resins.¹ They are made up of polypropylene oxide, also known as polypropylene glycol (PPG), which is terminated with hydrolyzable dimethoxysilyl groups. These resins cure at ambient temperature in the presence of moisture and a crosslinking catalysts.

MS polymers are very versatile resins and offer a wide range of physical properties. For example, the elongation at break can be adjusted from bleow 50 percent to well over 500 percent and the Shore A hardness down to 20², by adjusting the filler and plasticizer level and by blending with other suitable silane additives such as chain extenders, cross-linkers, water scavengers, and catalysts. They are also non-staining, are considered non-toxic, and provide excellent long-term adhesion to many substrates without significant changes in properties. Due to the good wetting properties, usually no pre-treatment of the substrates is required.

Silane-terminated polyethers are extensively used in moisture curing adhesives and sealants. Due to their flexibility and good adhesion to many substrates they provide durable, flexible and tear-resistant bonds with outstanding low temperature and weathering properties. They are known to combine the strength of polyurethanes with the weathering resistance of silicones.

Manufacturers & Distributors

¹The main components of MS poylmer resins are solvent- and isocyanate-free.

²Source: Wacker GENIOSIL^® brochure 'Alpha-Silane-Terminated Polymers', 2005