Morpholine is an organic chemical compound which have the chemical formula O(CH2CH2)2NH. This heterocycle, features both amine and ether functional groups. Because of the amine, morpholine is a base; its conjugate acid is called morpholinium. For example, neutralizing morpholine with hydrochloric acid makes the salt morpholinium chloride.

Applications

Rubber Chemicals

A  major  use  of  morpholine  is  as  an  intermediate  in  the  production  of delayed-action  type  rubber  accelerators.  Accelerators  are  added  to  rubber before  fabrication  to  increase  the  rate  of  vulcanization. Morpholine-based delayed-action accelerators are usually made by reacting morpholine with 2-mercaptobenzothiazole.  Several other morpholine-based accelerators have been reported in the literature.

Corrosion Inhibitors

Morpholine is widely used as a neutralizing amine in combating carbonic acid corrosion in condensate return lines of steam boiler systems. The morpholine volatilizes with the steam from the boiler and condenses when the steam does, thereby affording protection to the lines, which otherwise would be subjected to corrosion by the carbonic acid present in the steam condensate. Morpholine vapors protect silver and other metals against corrosion and tarnish by acid fumes, such as sulfur dioxide and hydrogen sulfide.

Morpholine is a component of a corrosion inhibitor system that prevents decomposition of a chlorinated hydrocarbon in a composition containing the chlorinated hydrocarbon and a large amount of water. Corrosion of metal aerosol containers and valves can be prevented by the use of low levels of morpholine.

Catalysts

Morpholine has been employed as a catalyst for the condensation of aldehydes and ketones which contain active methyl or methylene groups. The condensates may be hydrogenated to polyhydroxy compounds which can be sulfated to form surface-active agents. Morpholine has also been used as a gelling agent in the preparation of alumina catalysts for the treatment of hydrocarbons. Catalysts of fine particle size suitable for fluidized solid techniques result from this procedure.

Separating Agents

The physical and chemical properties of morpholine make it useful in various purification procedures. Marked differences in the solubility of the methyl amines in morpholine have led to a convenient extractive method for separating these volatile amines. The addition of morpholine to styrene-containing hydrocarbon mixtures makes possible the isolation of substantially pure styrene by azeotropic distillation. Morpholine is the preferred amine to use in an oil-amine mixture for scrubbing organic sulfur compounds from fuel gas. Morpholine is also used in the purification of acetylene and certain olefins.

Optical Brighteners

Morpholine is an important intermediate in the manufacture of optical brighteners. Optical brighteners are employed by the soap and detergent industry in the compounding of detergents. The diaminostilbene triazine type brightener with morpholine as a substituent on one of the triazine rings is particularly effective on cellulosics. Having greater stability to chlorine bleaches than other types of brighteners, they are particularly suitable for home laundry detergents.

Emulsion polymerization agent

Small  quantities  of  morpholine  are  used  in  the  emulsion  polymerization  of monomers, such as butadiene and isoprene, as well as their copolymerization with styrene, acrylonitrile, and the like.

Polymerisation inhibitor

Morpholine  has  been  used  as  a  temperature  sensitive polymerization inhibitor.  Small  amounts  permit  complete  impregnation  of  porous  materials with  molten  vinylpyrroletype  monomers  just  above  their  melting  points,  but still allow complete polymerization at slightly higher temperatures.

Process

Three methods of producing morpholine have been described:

a)  Reductive ammonation of diethylene glycol and hydrogen. Possible  catalysts  include  copper,  nickel,  cobalt,  chromium,molybdenum, manganese,  platinum,  palladium,  rhodium  and  ruthenium.  Morpholine is recovered by fractional distillation

b)    Dehydration  of  diethanolamine  with  a  strong  acid  such  as  oleum, concentrated  sulfuric  acid  or  concentrated  hydrochloric  acid.The  acid  is neutralized  by  the  addition  of  an  alkali  to  give  the  free  base  of  morpholine. Morpholine  is  recovered  by  extraction  using  an  organic  solvent  or concentrated aqueous alkali followed by distillation .

c.)  Heating  bis(chloroethyl)ether  and  anhydrous  ammonia  in  a  closed vessel.   After venting the  excess  ammonia,  the  product  is  filtered  from ammonium chloride, and purified morpholine obtained by distillation

Import and Export in India

The Import of Morpholine is about 2864 metric tonnes and the Export of Morpholine is about 691 metric tonnes.

Indian producers

Balaji Amines Ltd is the sole producer of morpholine in the country.

The company pioneered the manufacture of Morpholine& Alkyl Morpholines and N-Methyl  Morpholine  Oxide,  which  is  the  preferred  solvent  used  for  the manufacture of viscose staple fibre by the solvent spun process. The company’s range  of  alkyl  morpholines  include  lauryl,  methyl,  ethyl,  hydroxy  ethyl morpholines etc. A  new  plant  of 15000 tonnes  per  annum  capacity  for  manufacturing  GBL,  NMP/ 2P at MIDC, Chincholi, Solapur has been set up.

Global Producers

BASF Germany

Huntsman Corporation