High Cis Elastomeric Polyisobutylene HMW from Germany
High molecular weight (HMW) elastomeric polyisobutylene with high cis content, over 95% isobutylene by weight, imported as primary polymer under HTS 3902.20.10.00. Ideal for sealants, roofing membranes, and vibration dampeners due to superior elasticity. Primary form ensures classification before vulcanization.
Duty Rate — Germany → United States
10%
Rate breakdown
9903.05.3910%Section 301 (forced labor) — European Union member state (col1 rate < 10 percent): MFN < 10% → total duty capped at 10%
Import Tips
• Conduct FTIR spectroscopy for customs verification of structure
• Differentiate from butyl rubber copolymers to stay in 3902
• Beware of moisture absorption affecting elasticity claims