High Cis Elastomeric Polyisobutylene HMW
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.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If chemically modified with halogens
Halogenated derivatives like chlorobutyl are classified under 3907 per subheading note (a)(3) 'Other'.
If containing plasticizers over 50% by weight
Plasticized polymers meeting US note criteria shift to plates/sheets in 3920.43.
If peptizers or processing aids added
Rubber processing chemicals are in Chapter 35, not primary polymers.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right HTS code — and can price the duty on it in the same conversation.
Import Tips & Compliance
• Conduct FTIR spectroscopy for customs verification of structure
• Differentiate from butyl rubber copolymers to stay in 3902
• Beware of moisture absorption affecting elasticity claims
Related Products under HTS 3902.20.10.00
Elastomeric Polyisobutylene Rubber
Elastomeric polyisobutylene is a synthetic rubber polymer where isobutylene monomer units constitute 95% or more by weight, classified under HTS 3902.20.10.00 as elastomeric polyisobutylene in primary form. It is used in manufacturing tires, seals, and adhesives due to its high elasticity and impermeability to gases. This primary form excludes finished articles or compounded products.
Butyl Rubber Vistanex L-100
Vistanex L-100 is a high molecular weight elastomeric polyisobutylene with over 95% isobutylene content, imported in primary pellet form under HTS 3902.20.10.00. Known for tackiness, it serves as a pressure-sensitive adhesive base in tapes and sealants. Its elastomeric nature distinguishes it from rigid polyolefins.
Elastomeric Polyisobutylene Pellets for Tire Inner Liner
These pellets are elastomeric polyisobutylene with 97% isobutylene monomer content, designed for compounding into tire inner liners under HTS 3902.20.10.00. Their gas impermeability and elasticity qualify them as primary form elastomers. Supplied unvulcanized for downstream rubber processing.
Opanols Elastomeric Polyisobutylene Resin
Opanols are medium molecular weight elastomeric polyisobutylene resins meeting the 95% isobutylene criterion for HTS 3902.20.10.00 classification in primary forms like granules. Used in chewing gum bases and cable insulation for elasticity and moisture resistance. Excludes any finished plastic articles.