Thiol-Terminated Polysulfide Prepolymer LP-3

Thiol-Terminated Polysulfide Prepolymer LP-3 is a viscous, elastomeric liquid used in aerospace sealants and coatings. Classified under HTS 3911.90.10.00 for elastomeric polysulfides in primary forms per subheading rules on polymer content. Its mercaptan-terminated structure provides elasticity for high-performance applications.

Import Duty Rates by Country of Origin

Origin CountryMFN RateCh.99 SurchargesTotal Effective Rate
🇨🇳ChinaFree+35.0%35%
🇲🇽MexicoFree+10.0%10%
🇨🇦CanadaFree+10.0%10%
🇩🇪GermanyFree+10.0%10%
🇯🇵JapanFree+10.0%10%

Alternative Classifications

This product could be classified differently depending on its characteristics or intended use.

3907.99Lower: 16.5% vs 35%

If chemically modified with significant silane additives

Modified polymers not specifically covered go to 'Other' in 3907 series for polysiloxanes or derivatives.

3910.00.00Higher: 38% vs 35%

If for silicone-based elastomers

Silicones are distinctly classified in 3910, separate from polysulfides in 3911.

4006.90Lower: 12.7% vs 35%

If imported as unvulcanized rubber compound

Compounded with fillers or vulcanizing agents, it becomes Chapter 40 unvulcanized rubber.

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Import Tips & Compliance

Submit technical data sheets proving >95% polysulfide monomer content to qualify under 3911.90.10

Avoid misdeclaration as rubber by confirming it's unvulcanized primary form, not Chapter 40 material