I. a prepolymer component comprising an isocyanate-terminated prepolymer or quasi-prepolymer having an isocyanate content of 1 to 20 percent by weight, the prepolymer or quasi-prepolymer being a reaction product of 

a) at least one organic polyisocyanate having an isoqyanate equivalent weight of 80 to 250 and 

b-1) one or more polyols having a hydroxyl equivalent weight of greater than 250 g/mol and a nominal hydroxyl functionality of 2 to 4; and 

II. a separately packaged a curative component comprising b-2) one or more polyols having a hydroxyl equivalent weight of up to 260, wherein at least 50% by weight of b-2) is at least one alkoxylated Mannich base has an average hydroxyl functionality of 3 to 7. 

15. A sealant or adhesive formed by combining components I and II of the two-component sealant or adhesive composition of claim 14 at a ratio that produces an isocyanate index of 90 to 150 to form a reaction mixture and curing the reaction mixture to form a sealant or adhesive that includes a polyurethane polymer corresponding to the reaction product of components I and II, the polyurethane polymer having a hard segment content of 20 to 80% by weight. 

