Prehnitic Acid from China
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.
Duty Rate — China → United States
44%
Rate breakdown
9903.05.3112.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of China, as provided for in U.S. note 52 to this subchapter
9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
Import Tips
• 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