Liquid Polyisoprene Rubber (LIR) from Mexico
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.
Duty Rate — Mexico → United States
10%
Rate breakdown
9903.05.5510%Section 301 (forced labor) — additional 10% ad valorem on products of Mexico
Import Tips
• Specify molecular weight (e.g
• 3000-7000 g/mol) and polydispersity to confirm primary liquid polymer status
• Test for residual monomers; >5% may trigger copolymer classification rules
• Hazardous material declaration required for flammable liquids