US Patent 9309439 Sealant and adhesive using green prepolymer

A polyurethane prepolymer comprising the reaction product of a reactant formulation comprising a polyol entirely derived from a natural oil; a natural oil-petroleum blend polyol; an isocyanate, at least one catalyst, drying agent, and plasticizer, wherein the prepolymer has a bio-based content of from about 15% to about 75% by weight. The prepolymer may be used in adhesive, or sealant compositions.