Polyisobutylene Rubber PIB from China

Polyisobutylene (PIB) is a synthetic rubber polymer derived from isobutylene monomer, imported in primary pellet form under HTS 3902.90.0050 as 'other' olefin polymers. With isobutylene comprising over 95% by weight, it meets subheading note (a)(1) criteria. Used in chewing gum bases, adhesives, and sealants for its tackiness and impermeability.

Duty Rate — China → United States

31.5%

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)
9903.03.030%Articles the product of any country, as provided for in subdivision (aa)(ii) of U.S. note 2 to this subchapter

Import Tips

Include FTIR or NMR test reports proving >95% isobutylene monomer content

Label clearly as 'primary forms' to distinguish from compounded rubber products

Check for copolymer content; excess may reclassify under predominant monomer rule