Polyimide Prepolymer Powder from China
Thermosetting polyimide prepolymer powder in primary form for aerospace composites. Under 3911.90.91.50 as NES thermosetting product, classified by predominant imide monomer units.
Duty Rate — China → United States
44%
Rate breakdown
9903.88.0225%Except as provided in headings 9903.88.12, 9903.88.17, 9903.88.20, 9903.88.54, 9903.88.59, 9903.88.61, 9903.88.63, 9903.88.66, 9903.88.67, 9903.88.68, 9903.88.69, or 9903.88.70, articles the product of China, as provided for in U.S. note 20(c) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(d)
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China
Import Tips
• Include cure cycle instructions proving thermoset transformation from prepolymer state
• Test for 95% imide content to rule out copolymer shifts per subheading note (a)(2)
• Comply with ITAR if for defense applications; separate from tariff classification