Mixed alkoxysilyl functional polymers
View Patent ↗This invention relates to silylated polymers having mixed alkoxy groups on the silyl portion thereof, methods of their preparation, and compositions and reaction products formed therefrom. These alkoxysilylated polymers can be crosslinked when exposed to atmospheric moisture to become useful elastomers, sealants or adhesives. The presence of different alkoxy groups on the silicon atoms can control or otherwise moderate the cure speeds of these silylated polymers.
1. A method of making an alkoxysilyl endcapped polymer, comprising the steps of:
reacting a first reactant having the structure:
HO—R—OH
wherein R is a hydrocarbon diradical selected from the group consisting of polyesters, polyolefins, polyurethanes, poly(meth)acrylates and polyepoxide, any of which optionally includes heteroatom and/or silicone-containing linkages, and polysiloxanes, with a second reactant comprising a silyl having one end terminating with an isocyanate group and another end terminating with at least two alkoxy groups attached to a silicon atom thereof, wherein at least one of said alkoxy groups is not methoxy; and
providing for reaction as a third reactant a methoxy silane in amounts and for a time sufficient to achieve alkoxy exchange with said alkoxysilyl endcapped polymer wherein said alkoxysilyl endcapped polymer includes methoxy groups.