Trimellitic Anhydride

Chemical Properties

Trimellitic anhydride is a white powder or flakes. It is the anhydride of trimellitic acid (1,2,4-benzenetricarboxylic acid). It is soluble in water, ethanol, acetone and other general organic solvents.

Uses

Trimellitic Anhydride is mainly used as raw material for polyester resin,polyimide resin,plasticizer TOTM ,and also be used for producing heatproof & insulating,adhesive,surfactant, paint,synthesize dye materials etc. Trimellitic anhydride is used as an embossing agent for vinyl flooring and as a curing agent for epoxy resins. It is also used as an intermediate for the synthesis of surface coatings chemicals, adhesives, polymers, dyes printing inks, pharmaceuticals .

Uses

Trimellitic anhydride is mainly applied to produce good heat-proof, weather-proof and solvent-proof trimellitate plasticizers, among which the most popular product is tri(2-ethylhexyl)trimellitate. It is also used to synthesize polyester resins.TMA can also be applied to curing agent of epoxy resins.

Definition

ChEBI: Trimellitic anhydride is a 2-benzofuran compound having oxo groups at the 1- and 3-positions and a carboxy substituent at the 5-position; the cyclic anhydride formed from the carboxy groups at the 1- and 2-positions of trimellitic acid. It has a role as an epitope, an allergen and a hapten. It is a cyclic dicarboxylic anhydride, a dioxo monocarboxylic acid and a member of 2-benzofurans. It is functionally related to a phthalic anhydride and a trimellitic acid.

General Description

1,2,4-Benzenetricarboxylic anhydride(TA) is a hydrophilic monomer with multipurpose usage; as a curing agent for epoxy based resins and as a plasticizer for polyvinyl chloride(PVC).

Air & Water Reactions

Sensitive to moisture. Hydrolyzes slowly. Solutions in water or alcohol may be unstable. Insoluble in water.

Reactivity Profile

1,2,4-Benzenetricarboxylic anhydride reacts exothermically with water. This reaction is expected to be slow, but can become vigorous if local heating accelerates it. Reaction with water is accelerated by acids. Incompatible with acids, strong oxidizing agents, alcohols, amines, and bases. Incompatible with strong oxidizing agents, strong acids or strong bases. .

Hazard

Toxic by inhalation. Respiratory sensitization.

Health Hazard

Trimellitic anhydride (TMAN) causes both respiratory irritation and immunologic respiratory disease.

Safety Profile

Moderately toxic by ingestion. Has caused pulmonary edema from inhalation. Irritant to lungs and air passages. May be a powerful allergen. Typical attack consists of breathlessness, wheezing, cough, running nose, immunologcal sensitization, and asthma symptoms. When heated to decomposition it emits acrid smoke and irritating fumes. See also ANHYDRIDES.

Synthesis

3-Xylene is carbonylated with carbon monoxide in the presence of boron trifluoride and hydrogen fluoride to form 2,4-dimethylbenzaldehyde. 2,4-Dimethylbenzaldehyde is decomplexed from the acids, purified, and oxidized to trimellitic acid. Trimellitic acid is subjected to normal dehydration and purification steps to obtain high quality trimellitic anhydride.

Potential Exposure

TMA is used to produce trimellitate plasticizers, poly (amide-imide) polymers; in paints, enamels, and coatings; polymers, polyesters; as a curing agent for epoxy and other resins; in vinyl plasticizers; agricultural chemicals; dyes and pigments; pharmaceuticals, surface active agents; modifiers, intermediates, and specialty chemicals.

Carcinogenicity

There are no reports of carcinogenicity associated with TMAN exposure. It was not mutagenic in bacterial assays with or without metabolic activation. No teratogenic effects or developmental toxicity was seen in rats or guinea pigs exposed to 500mg/m3 for 6 hours/day during their period of major organogenesis.

Incompatibilities

Dust can cause an explosion. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Reacts slowly with water, forming trimellitic acid. Compounds of the carboxyl group react with all bases, both inorganic and organic (i.e., amines) releasing substantial heat, water and a salt that may be harmful.

Waste Disposal

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.