Isocyanatopropylmethyldimethoxysilane | Manta S121

Manta S121 is a bifunctional organosilane with a reactive isocyanate group and a methyldimethoxy silyl group. Standard trialkoxy silanes form rigid 3D crosslinked networks; the dialkoxy structure of S121 instead promotes linear chain extension during moisture curing.

This makes S121 an end-capping agent for producing elastic, low-modulus polymers with high elongation. The isocyanate group reacts rapidly with active hydrogen-containing species such as amines, hydroxyls and thiols, and the silane improves coupling and adhesion to organic and inorganic substrates.

S121 and Manta S122 are both dialkoxy isocyanatosilanes. S121 carries methoxy groups and releases methanol on hydrolysis, while S122 carries ethoxy groups and releases ethanol. Compared with the trimethoxy grade Manta S310, S121 gives lower crosslink density and a softer cured elastomer.

• Low-modulus MS and SPUR sealants: end-capping of polyols to synthesize high-movement silane-modified polymers and SPUR sealants for construction joints subject to thermal expansion and contraction
• Flexible adhesives and coatings: additive or modifier in polyurethane adhesives and coatings that need impact resistance, high flexibility and stress relaxation
• Coupling agent: coupling between inorganic substrates and amine- or hydroxyl-functional polymers

Supplied in 20 kg, 25 kg iron pail, 200 kg drum.