yes, n-methylmorpholine and water form a minimum boiling azeotrope consisting of 74.5% n-methylmorpholine and 25.5% water. the boiling point of the azeotrope is 114.5 °c.

azeotrope is a mixture of two or more liquids, at a certain has a constant boiling point and composition over the pressure range. azeotropes form when the intermolecular forces between molecules in a mixture are stronger than those in a pure liquid.

the formation of n-methylmorpholine-water azeotrope is due to the hydrogen bonds between n-methylmorpholine and water molecules are stronger than those between pure n-methylmorpholine or pure water molecules. stronger hydrogen bonds in the azeotrope prevent molecules from escaping into the gas phase until the temperature rises to 114.5 °c.