Abstract: Disclosed herein is a chemical resistant polyurea composition that may retain physical integrity even when continuously or semi-continuously exposed to a corrosive environment comprising alkalis or acids. The chemical resistant polyurea composition may be formed, in some embodiments, by a process including: reacting a polyalkadiene polyol with a polyisocyanate at a temperature and for a time sufficient to result in a polyurea prepolymer containing less than 5 wt. % NCO; admixing the polyurea prepolymer containing less than 5 wt. % NCO with a polyfunctional amine curing agent and at least one of a solvent, a UV absorber, an antioxidant, and a colorant to form a curable composition, wherein the polyurea prepolymer and the polyfunctional amine are admixed at a stoichiometric ratio, based on equivalents, in the range from about 1.03:1 to 1.08:1; and curing the curable composition to form the chemical resistant polyurea composition.

Abstract: A method of producing three dimensional polyurethane shapes by spray molding a quasi-gel like polymer precursor composition that is first mixed and then sprayed by a spray gun. The spray coating of quasi-gel polymer precursor composition subsequently cures to form a molded polyurethane polymer shape. Such artificial three dimensional shapes may include rocks, rock walls or faces, tree stumps or limbs, animals, architectural features or settings in which a certain visual appearance is desired.

Abstract: An improved method and composition for repairing cementitious surfaces is provided. A polymerizable urethane composition having an excess of isocyanate groups to account for water present in the reaction environment is utilized. The method utilizes water, e.g. surface moisture, to foam the polymer and provide a long-lived repair of the surface. The method is particularly applicable in the repair of concrete roadways.