Polyisobutylene Rubber Vistanex LM-MS from Mexico
Vistanex LM-MS is a medium molecular weight polyisobutylene polymer used primarily as a tackifier and viscosity modifier in adhesives, sealants, and rubber compounding. It falls under HTS 3902.20.5000 as 'Other' polyisobutylene in primary forms, meeting the subheading note where the isobutylene monomer units contribute over 95% by weight. This non-crosslinked elastomer is imported in pellet or slab form for industrial processing.
Duty Rate — Mexico → United States
16.5%
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
Import Tips
• Verify monomer content exceeds 95% isobutylene per Chapter 39 notes to avoid reclassification; provide supplier certificates of analysis for Customs; watch for blends exceeding 5% other monomers which shift to predominant monomer subheading