Urethane is another name for ethyl carbamate. This is a chemical that is composed of one central carbon that contains an ethyl ester. Attached to this carbon is also an amine (NH2). The combination of ester and amine allow for urethane molecules to form amide bonds together and form long polymeric chains (polyurethane). These two functional groups also give urethane a very high polarity which allows it to be soluble in many organic solvents. Because of this high polarity, pure, anhydrous (without any water) urethane is a crystalline solid with a relatively high melting point for such a small chemical compound.