An article to understand the properties and uses of maleic acid

[alias]Maleic acid, dehydrated malic acid, cis acid.

[Molecular formula]C4H4O4

[Structural formula]HOOCCH–CHCOOH

［Property］Maleic acid is a white monoclinic prismatic crystal, the industrial product is slightly yellowish, with a little astringency . The relative density is 1.590 (20°C), the melting point is 130-131°C, and it decomposes at 138°C. Soluble in water, ethanol, ether and acetone, etc., slightly soluble in benzene. When heated, it easily loses water to form maleic anhydride. It has active chemical properties and can perform reactions such as addition, self-polymerization, copolymerization, acylation, amidation, halogenation, hydrogenation, hydration, alkylation, decarboxylation and isomerization.

［Application］Organic synthesis raw material, used for the manufacture of tartaric acid, succinic acid and unsaturated resin, is used for the manufacture of malathion, Raw materials of clothing medicines such as maleic hydrazide, captan, captafol, and algae. It is also used in the manufacture of coatings, dye auxiliaries, fluorescent whitening agents, plasticizers, lubricating oil pour point depressants, paper treatment agents and water quality stabilizers, etc. It is also used as a preservative for oil and grease.

[Brief recipe]

①Using benzene as raw material, maleic anhydride is first produced by air oxidation under the action of vanadium catalyst, and then absorbed by water, crystallized and dried to obtain maleic anhydride Acenoic acid.

②Using butene or butane as raw material, under the action of vanadium catalyst, maleic anhydride is first produced by air hydrogenation, and then absorbed by water, concentrated and dried Produces maleic acid.

③ When naphthalene is used as raw material to oxidize phthalic anhydride, the by-product maleic anhydride is obtained, which is then absorbed by water, crystallized and dried. Maleic acid.

[Safety and Protection]Packed in a woven bag lined with a plastic bag, with a net weight of 25kg. Store in a cool dry place.

This product is poisonous. Skin contact with liquid acid can cause burns, and splashing into eyes can cause conjunctivitis, and in severe cases, it can cause vision loss or even blindness. Rinse with plenty of water after skin contact.