Why does isopropyl alcohol evaporate quickly?

The intermolecular forces that operates between isopropanol molecules are (i) hydrogen bonding, and (ii) dispersion forces between the alkyl residues. (i) is probably the most significant contributor, and it reduced by comparison with say, water, because there is only the one ""^(delta-)O-H^(delta+) dipole in isopropanol.
As a chemist, as a physical scientist, you should look up the normal boiling points of water, isopropyl alcohol, $n$-propanol, and ethyl alcohol, and see if you can identify any other significant contributors.