Chemical Industry-Epoxidation

H₂0₂ and peracids will react with unsaturated compounds to produce epoxides. Epoxidation is an oxygen-transfer reaction, for which hydrogen peroxide and its derivatives are very well suited. This is reflected in the fact that a wide variety of peroxygen systems have been applied to a range of olefin types, and some of these applications are among the long established industrial uses of peroxygen products.

Epoxides are valuable and versatile commercial intermediates owing to the large range of reactions they undergo. The majority of transformations occur with active hydrogen compounds such as ammonia, amines, organic acids, alcohols and sulphur compounds.

'In-Situ' Percarboxylic Acids

The simplest and generally most economic way to carry out an epoxidation is to generate the peracid (performic acid or peracetic acid) in the reaction medium.

Epoxidation with 'in-situ' performic is an established commercial process. Major applications are the epoxidation of long chain olefins (usually of soya-bean oil). The resulting epoxides are relatively stable to ring opening. Vegetable oils, polybutadiene, natural and synthetic rubbers, and polyesters have been epoxidized by this procedure.

Cation exchange resins are also employed as catalysts for 'in-situ' peracetic acid (PAA) and reduce epoxide losses, particularly in the presence of hydrocarbons, or chlorinated solvents. This has been used to effect the epoxidation of soya-bean oil to a high grade epoxy soya-bean oil, and for polybutadiene epoxides.

Direct Methods

The only widely adopted direct method of epoxidizing olefins using H₂O₂ is under alkaline conditions. Alkaline H₂O₂ has the advantage of being cheap and convenient to operate. However, chemically its use is restricted to the epoxidation of olefins deactivated by electron withdrawing groups. Industrial processes must be designed with care as H₂O₂ rapidly decomposes at high pH and organic peroxides can be formed as by-products of the reaction.

For a more detailed discussion on this application of peroxygen technology please contact us

	INTEROX CG 35
	INTEROX CG 50
	INTEROX CG 60
	INTEROX CG 70
	INTEROX ST 35
	INTEROX ST 50
	INTEROX ST 60
	INTEROX ST 70

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