Polymers are assigned CAS Registry Numbers® based on:
- Monomers
- Structural repeating unit (SRU)
- Manual registration (unknown/proprietary composition)
Search polymers by:
- Polymer formula (tips below)
- Monomer structures (as separate fragments)
- Class or descriptive term
Search tips
- Use the Single Component filter to separate out mixtures (this will retain covalently bonded components as in polymers).
- Further refine by Exact Chemical Structure of specific monomers to filter out structural isomers
- Polymer searching webinar
Searching by formula
Polymer records have unique formats for molecular formula, based on either monomers or SRU. Component formulas are expressed in Hill order (carbons, hydrogens, then other atoms in alphabetical order).
- Monomer Formulas: addition polymers and most condensation polymers include the formula(e) of the monomers within brackets and closed with an “X”
- Homopolymers: monomer in parentheses with “x”.
(C3H6)x
- Copolymers: monomers separated by dots in parentheses with “x”.
(C15H16O2.C3H5ClO)x
- SRU Formulas: structural repeating units of symmetric condensation polymers include the formula of the repeating unit within brackets and closed with an “N”
- SRU: SRU in parentheses with “n”.
(C10H8O4)n
- End Groups: single molecular formula following SRU formula.
(C3H6O)nC6H16N2O