What Is Itaconic Acid?
Itaconic Acid is an aliphatic dicarboxylic acid, an isomer of mesaconic acid and citraconic acid.
Itaconic Acid is a colorless, hygroscopic crystal with a characteristic odor. It is also known as methylene succinic acid. It is soluble in water and ethanol, but insoluble in benzene, chloroform, and ether.
It is a 5-carbon dicarboxylic acid produced by fungi and has a special molecular structure with vinylidene groups (exomethylene groups). Its CAS number is No. 97-65-4.
Uses of Itaconic Acid
Itaconic Acid is used in the following applications:
1. Raw Material for Polymers
The double bond in itaconic acid causes radical polymerization. Since it is a dicarboxylic acid, it can be polymerized with diol compounds and converted into polyesters. Copolymerization of itaconic acid ester with other monomers has been commercialized by many companies.
Addition of itaconic acid esters to polymers improves photostability, surface hardness, heat resistance, internal plasticity, adhesion, solvent resistance, and water resistance.
Itaconic acid esters, like acrylic esters, are widely used in paint bases, paper and leather coatings, fiber processing, adhesive wax bases, synthetic rubbers, and adhesives. They are also used in ion exchange resins, ABS resins, and AS resins (acrylonitrile-styrene copolymerization).
2. Food Additives, Agricultural Chemicals, Etc.
Itaconic acid is a food additive. It is used as an acidifier and pH adjuster.
It is also used as a pesticide as an apple pesticide and plant growth regulator. It is believed that when applied after pollination of the apical bud center flower is completed, it causes inhibition of pollen tube elongation or inhibition of fertilization by burning of the column head due to organic acids, thereby producing the effect of flower plucking.
It is also highly regarded as a safe substance used as a raw material for printing inks, dental cement, and industrial cement.
Properties of Itaconic Acid
Itaconic acid is a colorless, hygroscopic crystal with a characteristic odor. Its melting point is 164-168℃ (decomposition). It is well soluble in water, soluble in ethanol, and slightly soluble in benzene, chloroform, ether, etc.
Other Information on Itaconic Acid
1. Handling Precautions
Itaconic acid is an extremely safe compound, however because it is an acidic substance, protective equipment (gloves, glasses, mask, etc.) must be worn when handling it. It is important not to store it with alkaline substances and to store it in a cool, well-ventilated place.
2.Anti-Inflammatory Effects
It has recently been discovered that itaconic acid itself has anti-inflammatory properties. It has also been found that compounds such as protolichesterinic acid, which has the molecular skeleton of itaconic acid in their molecules, exhibit a variety of physiological activities, including antibacterial, antioxidant, anti-inflammatory, antitumor, and plant growth regulating activities.
These activities are presumed to be derived from the α,β-unsaturated carbonyl structure, but the details are not known. Thus, compounds with the molecular skeleton of itaconic acid and its derivatives are promising as pharmaceutical raw materials.
3. SDGs With Itaconic Acid
Since most of the raw materials for polymers are petroleum, there are concerns about resource depletion, increasing CO2 concentration, and worsening global warming.
For example, polystyrene is made by polymerizing styrene, which is synthesized from ethylbenzene, and ethylbenzene is produced from petroleum. Producing petroleum-derived polymers is considered contrary to sustainable economic activities (SDGs).
In contrast, if polymers can be synthesized from plant resources that grow while taking in CO2 from the atmosphere, global warming can be expected to be curbed through the CO2 cycle. Polymer biopolymers (polymers using biomass) are attracting attention.
Itaconic acid is one of the polymers that can be obtained from plant resources by fermentation, and is a representative example of a biomass-utilizing polymer. It is also one of the 12 biobased key chemicals proposed by the U.S. Department of Energy.
Currently, research on polymers made from biomass such as itaconic acid and research on microorganisms that produce itaconic acid is active.