Patent GB-788531-A (GB)
Title: Diepoxides and process of producing the same
Filed: 1955-03-22
Abstract: An alkenyl ester of a diepoxy fatty acid is obtained by reacting peracetic acid with an alkenyl ester of a dienoic fatty acid at a temperature within the range of - 10 DEG  C. to 75 DEG  C.  The invention also comprises as new products vinyl 9, 10, 12, 13 diepoxystearate and allyl 9, 10, 12, 13 diepoxystearate.  In the epoxidation process it is preferred to provide an excess of from 10 to 25 mol. per cent peracetic acid in the reaction mixture and to use the peracetic acid in the form of a solution thereof in an inert volatile organic solvent, e.g. acetone.  After the reaction is complete the solvent is removed from the mixture and acetic acid and any unconsumed peracetic acid are then removed, e.g. by distillation or extraction.  The preferred method of separation is to add the reaction mixture to a kettle-still containing ethylbenzene which is refluxing at about 25 mm. of Hg. pressure and then distilling off the volatile solvent (e.g. acetone), peracetic acid, acetic acid, and ethylbenzene.  The residue product may be further purified by continuous distillation at pressures of from one to two mm. of Hg. Examples are given for the epoxidation of: (1) the allyl ester obtained by esterifying a commercial mixture of fatty acids consisting of oleic acid and linoleic acid and small amounts of linolenic acid and of saturated acids above lauric acid with allyl alcohol in the presence of toluene and concentrated sulphuric acid as catalyst; and (2) the allyl ester of linoleic acid (obtained from safflower oil), the allyl ester being obtained by esterifying linoleic acid with allyl alcohol in the presence of benzene and of concentrated sulphuric acid as catalyst.  The epoxidation is carried out by means of a solution of peracetic acid in acetone and the epoxidized product is recovered as above by adding the reaction mixture to a kettle still containing ethyl benzene refluxing at 25 mm. Hg. pressure. Purified allyl 9,10,12,13-diepoxy stearate is recovered in (2) and it is stated that vinyl linoleate can be epoxidized in a similar manner to yield vinyl 9,10,12, 13-diepoxystearate.  The diepoxides are stated to be useful as plasticizers and stabilizers for synthetic resins and to be capable of forming polymers (see Group IV (a)) having a diversity of properties on account of the presence in the monomer of epoxide groups and an olefinic group. The linoleic acid used in Example (2) is prepared by refluxing safflower oil with a solution of KOH in methanol for two hours and then removing the methanol by distillation.  Water and cold dilute sulphuric acid are added to the residue and the fatty acid layer is separated, washed with hot water, filtered while hot, and then dried at 140 DEG  C.  The resulting crude acid mixture is then added to a solution of urea in hot methanol and the mixture is heated to effect complete solution and then cooled and filtered. Methanol is evaporated from the filtrate and water is then added followed by a small amount of concentrated HCl.  After heating for a short period the water layer is drained off from the acid layer and the latter distilled twice through a packed column to yield a product analysing 96.2 per cent as linoleic acid. Specification 788,530 is referred to.ALSO:Alkenyl esters of diepoxy fatty acids, e.g. allyl and vinyl 9,10,12,13-diepoxystearates, which are obtainable by reacting peracetic acid with an alkenyl ester of a dienoic fatty acid (see Group IV (b)) are stated to be useful as plasticizers and stabilizers for synthetic resins.  They may be polymerized to form insoluble and infusible polymers.  Since the esters contain an epoxide group and an olefinic group, they can be subjected to conditions whereby polymerization occurs only through one type of group and the resulting polymer can then be further polymerized under different conditions through the second type of group to form an infusible and insoluble polymer.  Specification 788,530 is referred to.