• Top library match: Poly(ethylene glycol methyl ether) #74696

• All listed library similarities are effectively zero, S-O the retrieval does not provide strong discriminating support for a specific named material.
• The 1728 cm-1 carbonyl band is a limiting feature for assigning the sample as simple Poly(ethylene glycol methyl ether) without qualification.
• It remains unclear whether the carbonyl band at 1728 cm-1 belongs to the main material, an end group, an oxidized fraction, an ester-containing additive, or a mixture component.
• The present evidence supports a broad oxygenated ether/polyether direction more strongly than a single discrete library entity.
• Without stronger matching bands or corroborating references, the chain length, end-group identity, and sample purity cannot be established from this FTIR result alone.

Recommended next steps: Re-examine the sample for the presence and intensity of a broad O-H band in the 3200-3600 cm-1 region to distinguish hydroxyl-terminated polyether material from a fully etherified analogue. Check for additional carbonyl-associated bands near 1170-1300 cm-1 and 1735-1750 cm-1 to determine whether an ester-containing additive or oxidation product is present. Compare against authenticated FTIR references for Poly(ethylene glycol methyl ether), Poly(ethylene oxide), and common esterified polyether materials under the same sampling conditions. Use complementary GC-MS or LC-MS for lower-molecular-weight material, or NMR if feasible, to verify whether the sample is a single methyl-terminated polyether or a carbonyl-containing mixture.