Thiol-Terminated Polysulfide Prepolymer LP-3 from China

Thiol-Terminated Polysulfide Prepolymer LP-3 is a viscous, elastomeric liquid used in aerospace sealants and coatings. Classified under HTS 3911.90.10.00 for elastomeric polysulfides in primary forms per subheading rules on polymer content. Its mercaptan-terminated structure provides elasticity for high-performance applications.

Duty Rate — China → United States

35%

Rate breakdown

9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
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)

Import Tips

Submit technical data sheets proving >95% polysulfide monomer content to qualify under 3911.90.10

Avoid misdeclaration as rubber by confirming it's unvulcanized primary form, not Chapter 40 material