How do the ester group and the amine affect the properties of urethane?
Urethane is the common name for ethyl carbamate. Its chemical formula is CH3CH2O2CNH2. It is basically an ethyl ester with an extra amine attached to the carbonyl carbon. This functional group is called a carbamate. As a result, urethane is extremely polar and can dissolve in water and a variety of organic solvents. Its polarity also makes it a crystalline solid in pure, dried form. Perhaps most importantly, the ester and amine groups allow for the formation of polymers called polyurethane. Polyurethane is a polymeric chain of monomers that are connected by urethane carbamates. The amine of urethane can form an amide bond with the ester of another carbamate to form these polyurethane polymers.