Silane modified polymers with improved properties

A moisture curable composition comprising a physical blend of:

• a moisture curable, silane modified polymer of structure (I)
• B(-An-R—SiXYZ)I (I).
• wherein B is an organic polymer backbone and B will not be a siloxane backbone,
• A is a divalent linking group linking the polymer backbone to the R1 group,
• I is an integer from 1 to 6,
• n is 0 or 1,
• R is a divalent C1-C12 hydrocarbon group that optionally comprises a heteroatom,
• at least one of X, Y and Z is a hydrolysable group;
• a moisture curable, silane functional additive having 3 or more —SiXYZ groups, wherein X, Y and Z are each independently selected from the group consisting of hydrogen, C1-C8 alkyl group, C1-C8 alkoxy group, wherein at least one of the substituents X, Y, Z must be a hydrolyzable group, the silane functional additive being the reaction product of a mixture comprising an isocyanotosilane and a polyol selected from a polyol having a linear ethylene oxide backbone free of nitrogen atoms and a functionality of 3 to 4, a polyol having a linear tetramethylene oxide backbone free of nitrogen atoms and a functionality of 3 to 4, and combinations thereof, wherein the polyol is free of propylene oxide;
• and
• a crosslinker different from the silane modified polymer and the silane functional additive;
• wherein cured reaction products of the moisture curable composition have greater strength and greater elongation compared to the moisture curable composition without the moisture curable, silane functional additive.