Chemical derivatives of natural rubber
Natural polymers (for example, alginic acid) and modified natural polymers (for example, hardened proteins, chemical derivatives of natural rubber), not elsewhere specified or included, in primary forms: > Other: > Chemical derivatives of natural rubber
Duty Rate (from China)
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
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)
Products classified under HTS 3913.90.10.00
Chloroprene Rubber (CR)
Chloroprene rubber, a synthetic elastomer produced by polymerization of chloroprene (2-chloro-1,3-butadiene), is a chemical derivative of natural rubber isoprene structure. It is supplied in primary forms such as bales or pellets for use in manufacturing weather-resistant products like wetsuits and hoses. Classified under HTS 3913.90.1000 as it qualifies as a chemical derivative of natural rubber per chapter notes on polymers.
Cyclized Rubber (Alkylated Chlorosulfonated Rubber)
Cyclized rubber is produced by treating natural rubber with sulfuric acid or other agents to create cyclic structures, yielding a harder derivative used in paints and varnishes. It appears in primary flake or powder form. Falls under HTS 3913.90.1000 as a chemical derivative of natural rubber not elsewhere specified.
Hydroxyl-Terminated Polyisoprene (HTPI)
HTPI is a telechelic natural rubber derivative with hydroxyl end-groups, used as a reactive prepolymer in polyurethane elastomers and adhesives. Supplied as viscous liquid or solid in drums. HTS 3913.90.1000 covers this chemically modified natural rubber in primary form.
Epoxidized Natural Rubber (ENR)
ENR results from partial epoxidation of natural rubber's double bonds, improving oil resistance for tire compounds and adhesives. Available in latex or solid bale primary forms. Chemical modification places it definitively under HTS 3913.90.1000.
Gutta-Percha Resin
Gutta-percha, a trans-1,4-polyisoprene from Palaquium trees, is chemically similar to natural rubber but more rigid; used in golf balls and dental applications. Processed into primary resin pellets. As a natural polymer chemical derivative, it fits HTS 3913.90.1000.
Maleated Natural Rubber (MNR)
MNR features maleic anhydride grafted onto natural rubber backbone for better adhesion in rubber composites. Supplied as primary crumb or powder. Grafting qualifies it as chemical derivative under HTS 3913.90.1000.
Liquid Polyisoprene Rubber (LIR)
LIR-3000/700 series are low molecular weight liquid derivatives of natural cis-1,4-polyisoprene, used as reactive plasticizers in tires and sealants. Primary liquid form in drums. Chemical degradation/polymerization modification places under HTS 3913.90.1000.
Thermoplastic Natural Rubber (TPNR)
TPNR dynamically vulcanizes natural rubber within thermoplastic matrix, creating processable pellets for injection molding. Primary pellet form. Blends chemically cross-linked qualify as modified natural polymer under 3913.90.1000.