Itaconic acids

White crystals m.p. 162-164 C. ll can be prepared by the fermentation of sugar with the mould Aspergillus lerreus or by healing citra-conic anhydride with water at ISO C. Electrolysis of the potassium salt in solution gives allene. Itaconic acid is used as a comonomer in plastics its esters are polymerized to lubricating oils and plasticizers. 

Itaconic 2Lcid[97-65-4] (methylenebutanedioic acid, methylenesuccinic acid) is a crystaUine, high, melting acid (mp = 167-168) produced commercially by fermentation of carbohydrates (1 4). Itaconic acid is produced in the broth from citric acid (qv). Isolated from the pyrolysis products of citric acid in 1836, this a-substituted acryUc acid received its name by rearrangement of aconitic, the acid from which it is formed by decarboxylation. 

Itaconic acid (1) is isomeric with citraconic [498-23-7] (2) and mesaconic [498-24-8] (3) acids. Under acidic, neutral, or mildly basic conditions and at moderate temperatures, itaconic acid is stable. At elevated temperatures or under strongly basic conditions, the isomers are interconvertible. 

Itaconic acid, anhydride, and mono- and diesters undergo vinyl polymerization. Rates of polymerization and intrinsic viscosities of the resulting homopolymers ate lower than those of the related acrylates (see Acrylic ester polymers) (8,9). 

Itaconic acid is a specialty monomer that affords performance advantages to certain polymeric coatings (qv) (see Polyesters, unsaturated). Emulsion stabihty, flow properties of the formulated coating, and adhesion to substrates are improved by the acid. Acrylonitrile fibers with low levels of the acid comonomer exhibit improved dye receptivity which allows mote efficient dyeing to deeper shades (see Acrylonitrile polymers Fibers, acrylic) (10,11). Itaconic acid has also been incorporated in PAN precursors of carbon and graphite fibers (qv) and into ethylene ionomers (qv) (12). 

Condensation with Aldehydes and Ketones. Succinic anhydride and succinic esters in the presence of different catalysts react in the gas phase with formaldehyde to give citraconic acid or anhydride and itaconic acid (94—96). Dialkyl acyl succinates are obtained by reaction of dialkyl succinates with C 4 aldehydes over peroxide catalysts (97). 

Small concentrations of vinylcarboxyhc acids, eg, acryhc acid, methacrylic acid, or itaconic acid, are sometimes included to enhance adhesion of the polymer to the substrate. The abihty to crystalline and the extent of crystallization are reduced with increa sing concentration of the comonomers some commercial polymers do not crystalline. The most common lacquer resins are terpolymers of VDC—methyl methacrylate—acrylonitrile (162,163). The VDC level and the methyl methacrylate—acrylonitrile ratio are adjusted for the best balance of solubihty and permeabihty. These polymers exhibit a unique combination of high solubihty, low permeabihty, and rapid crystallization (164). 

A number of patents describe accelerators that will reduce the time required for stabilization (24,27,28). The accelerators are often inherent to the polymer or precursor but may be added to the gas phase during stabilization. For example, it is common to have an acid group present as comonomer such as itaconic acid [97-65-4] or methacrylic acid [79-41-4]. The acid groups provide initiation sites for cyclization. Alternatively, the stabilization atmosphere composition can be modified to accelerate stabilization (29). 

Decomposition. When heated above 175°C, citric acid decomposes to form aconitic acid [499-12-7] citraconic acid [498-25-7], itaconic acid [97-65 ], acetonedicarboxyhc acid [542-05-2], carbon dioxide, and water, as shown in Figure 1. 

Fig. 1. Thermal decomposition of citric acid (1) to aconitric acid (2), citraconic acid (3), itaconic acid (4), and oxidation to acetonedicarboxylic acid (5).

Itaconic acid (2-propen-l,2-dicarboxylic acid) [97-65-4] M 130.1, m 165-166 , pK, 3.63, pK 5.00. Crystd from EtOH, EtOH/water or EtOH/ benzene. 

Because the polymer degrades before melting, polyacrylonitrile is commonly formed into fibers via a wet spinning process. The precursor is actually a copolymer of acrylonitrile and other monomer(s) which are added to control the oxidation rate and lower the glass transition temperature of the material. Common copolymers include vinyl acetate, methyl acrylate, methyl methacrylate, acrylic acid, itaconic acid, and methacrylic acid [1,2]. 

Maleic, fumaric, glutaconic, citraconic, mesaconic and itaconic acid... 

Campaigne et al. have used 3-thenyl bromide obtained by benzoyl peroxide-catalyzed, side-chain bromination of 3-methylthiophene with A -bromosuccinimide, as a starting material for 3-substituted thiophenes. - 22 3-Methylthiophene is now prepared commercially from itaconic acid. The reactive halogen in 3-thenyl bromide could be directly reacted with a variety of nucleophiles, such as cyanide, or malonate, to give more complex 3-substituted compounds. 3-Thenyl bromide was converted by the Sommelet reaction to 3-thio-phenealdehyde which, with silver oxide, was oxidized to 3-thio-... 

Originally itaconic acid was produced chemically by the pyrolysis of dtric add. The treatment results in water loss converting dtric add to aconitate. Subsequent decarboxylation of the latter gives two isomers, itaconic add and dtraconic add. The process was not very successful, partiy because sucdnate and itatartaric adds were also produced. 

C. Itaconic Acid, Citraconic Acid, and Mesaconic Acid... 

GC separation of derivatized carboxylic acids, 46-52 bacterial fatty acids, 51-52 bile acids, 50-51 C6-C24 monocarboxylic acids and dicarboxylic acids, 51 cyano acids, 52 higher-boiling acids, 49 itaconic acid, citraconic acid, and mesaconic acid, 49... 

TNMe on alkaline hydrolysis. In an ion exclusion-partition chromatographic method for the sepn of acids, TNMe emerged from the column betw citric and itaconic acids (Ref 36) Impact Sensitivity. On the BRL machine (1kg wt), using a noisemeter to detect explns, the 50% expin height was found to be 218cm. A 50/50 mixt with kerosene had a 50% expln height of 130cm (Ref 21)... 

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