Jump to navigation Jump to search


A colorless, Hygroscopic liquid with a characteristic amine odor. Morpholine is miscible with water, but it evolves heat in the process forming a basic solution that can saponify dried oil films and aid in their removal. Morpholine is also used to dissolve resins, waxes, Casein, Shellac, and dyes. It can also act as a Surfactant and Emulsifier. Morpholine has been used as a corrosion inhibitor in fire sprinkler and HVAC systems. It has also been used as a vapor phase neutralizing/alkalizing agent, but it is not recommended because of its toxicity, disagreeable odor, and poor ability to provide residual alkalinity. Some materials treated with morpholine, such as Leather and Pyroxylin coated book covers, have exhibited color changes (Book and Paper Catalog).

Chemical structure


Synonyms and Related Terms

tetrahydro-1,4-oxazine; diethylene oximide; diethylene imidoxide


  • Flammable, moderate fire risk. Flash point = 38C
  • Toxic by inhalation, ingestion and skin absorption.
  • Skin contact causes irritation.
  • ThermoFisher: SDS

Physical and Chemical Properties

Soluble in water and organic solvents.

Vapor pressure = 8.0 at 20C

Composition C4H8ONH
CAS 110-91-8
Melting Point -4.9 C
Density 1.007 g/ml
Molecular Weight mol. wt. = 87.1
Boiling Point 128.9 C

Resources and Citations

  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 6362
  • R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
  • Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
  • Hermann Kuhn, Conservation and Restoration of Works of Art and Antiquities, Butterworths, London, 1986
  • Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002
  • Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989