Spiro Phosphonate Monomer for Polymer Synthesis
This research-grade spiro phosphonate monomer, chemically 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, is used in copolymer production. It qualifies under HTS 2931.48.00.00 for its organo-inorganic phosphorus structure excluding halogens.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If containing heterocyclic nitrogen rings
Heterocyclic compounds with nitrogen take precedence in 2933 over organo-inorganic if applicable.
If imported dissolved in solvents for safety transport exceeding limits
Excess solvent makes it a preparation unsuitable for general use per Chapter 29 note (e).
If monohydric alcohol function is primary
Classification follows the latest numerical heading for esters/alcohols per note 5(A).
Not sure which classification is right?
Our AI classifier can analyze your specific product and recommend the correct HTS code with confidence.
Import Tips & Compliance
• Request Certificate of Analysis (CoA) specifying >98% purity to meet 'chemically defined' criteria
• Segregate from solvents to avoid note (e) issues
• Monitor REACH-like regulations for phosphorus compounds
Related Products under HTS 2931.48.00.00
3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide
This is a specific non-halogenated organo-phosphorus compound featuring a spirocyclic structure with two phosphonate groups, classified under HTS 2931.48.00.00 as an organo-inorganic compound where phosphorus is directly linked to carbon. It is used primarily as a synthetic intermediate in pharmaceutical and agrochemical production.
Antioxidant 552 (3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide)
Antioxidant 552 is the commercial grade of 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, a non-halogenated organo-phosphorus stabilizer for polymers. It falls under HTS 2931.48.00.00 due to its specific spiro phosphonate structure with P-C bonds, as defined in Chapter 29 heading 2931.
DOPO Derivative 3,9-Dimethylspiro Phosphonate
A DOPO-based derivative, this compound is precisely 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, used in flame-retardant synthesis for electronics. Classified in HTS 2931.48.00.00 as a non-halogenated organo-phosphorus compound per Chapter 29 definitions.
CAS 65481-32-7 3,9-Dimethylspiro[5.5]undecane Phosphonate Dioxide
Identified by CAS 65481-32-7, this is pure 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, a building block for organophosphorus ligands. HTS 2931.48.00.00 covers it as a non-halogenated organo-phosphorus derivative.