Polyurethane-33 is a complex polymer formed by reacting dimethylolpropionic acid and a polyester composed of Adipic Acid, Hexylene Glycol, Neopentyl Glycol with methylene dicyclohexyldiisocyanate (SMDI) to form a prepolymer. The prepolymer is neutralized with triethylamine and then chain-extended with hydrazine