Embodiments of the invention relate to crosslinkable silyl group-containing polymers and methods of producing them. In one embodiment a method of producing a silyl polymer is provided. The method includes reacting at least one natural oil based polyol with at least one isocyanate to form at least one prepolymer having at least one NCO group. The at least one natural oil based polyol includes the reaction product of hydroxymethylated fatty acids or esters thereof and at least one polyol initiator. The prepolymer having at least one NCO group is reacted with at least one amino functional alkoxy silane to form the silyl polymer, such that the silyl polymer includes at least one crosslinkable silyl group, at least one urethane group, and at least one urea group in each molecule.