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