Prehnitic Acid
Prehnitic acid (benzene-1,2,4,5-tetracarboxylic acid) used in polyimide films and high-performance composites. Identical reactivity to pyromellitic acid but different substitution pattern. HTS 2917.39.70.00 as aromatic polycarboxylic acid, other.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If 3,5,6-pyromellitic acid derivatives
Specific pyromellitic provisions precede general 'other' category.
If technical grade <90% purity
Chapter Note 1(a) requires separate chemically defined compounds.
If esterified with glycols
Chapter Note 5(A) but polymer esters move to Chapter 39.
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Import Tips & Compliance
• Synonymous with pyromellitic acid in commerce; position isomers rarely distinguished
• Composite prepreg manufacturers require lot-specific DSC thermal analysis
• Distinguish monomer from Chapter 39 low MW prepolymer by GPC analysis
Related Products under HTS 2917.39.70.00
Isophthalic Acid Technical Grade
Isophthalic acid is a meta-substituted aromatic dicarboxylic acid used in alkyd resins, polyester coatings, and copolyesters. Classified under HTS 2917.39.70.00 as an aromatic polycarboxylic acid not specifically enumerated elsewhere in heading 2917. This meta-isomer provides superior chemical resistance in coatings.
1,2,4,5-Tetracarboxybenzene (Pyromellitic Acid)
Pyromellitic acid, the diacid precursor to PMDA, is used in specialty polyimides and electronic materials. Classified under HTS 2917.39.70.00 as an aromatic polycarboxylic acid (four -COOH groups on benzene). Typically handled as dihydrate form.
Benzene-1,2,3-tricarboxylic Acid (Hemicellic Acid)
Hemicellic acid is a tri-carboxylic aromatic acid used in resin synthesis and as a pharmaceutical intermediate. It falls under HTS 2917.39.70.00 as an aromatic polycarboxylic acid not otherwise specified. The 1,2,3-substitution pattern gives unique reactivity.
Diphenic Acid
Diphenic acid (2,2'-biphenyldicarboxylic acid) is used in polymer synthesis and as a chiral resolving agent. Although biphenyl-based, classified under HTS 2917.39.70.00 as aromatic polycarboxylic acid per Chapter 29 structure. Provides rigid linker in specialty polymers.
Mellophanic Acid
Mellophanic acid (benzene-1,2,3,5-tetracarboxylic acid) serves as a monomer for heat-resistant polymers and electronic materials. Classified HTS 2917.39.70.00 as aromatic polycarboxylic acid with unsymmetrical substitution. Enables cross-linked network structures.
Benzene-1,3,5-tricarboxylic Acid (Trimesic Acid)
Trimesic acid features symmetrical 1,3,5-tri carboxylic substitution on benzene, ideal for metal-organic frameworks (MOFs) and coordination polymers. HTS 2917.39.70.00 aromatic polycarboxylic acid. Perfect 120° linker geometry.