• Top library match: Poly(vinyl methyl ether) #26275

• Direct literature evidence associates the 1098 cm⁻¹ band with a C–S single bond in copper(II) complexes [1] and with aromatic C–H in‑plane bending in herbal medicines [S3]; these assignments correspond to unrelated material systems and do not support the polyether direction, but they do not contradict it at the functional‑group level.
• The conclusion is based on a single spectral peak and a moderate library similarity score (0.758). The absence of companion bands—such as aliphatic C–H stretching around 2900 cm⁻¹, the symmetric C–O–C stretch near 850–950 cm⁻¹, or methoxy deformation bands—prevents full verification of the proposed polymer structure.
• Alternative polyethers (e.g., poly(ethylene glycol) methyl ether) and even non‑polymeric materials (e.g., magnesium sulfate heptahydrate) appear among the top library hits, indicating that the single available peak is not sufficiently distinguishing.

Recommended next steps: Acquire a full‑range spectrum (4000–400 cm⁻¹) of the sample to observe the aliphatic C–H stretching region and the fingerprint pattern characteristic of poly(vinyl methyl ether). Compare the complete spectrum with a certified reference sample of poly(vinyl methyl ether) or a well‑established spectral library to confirm the methoxy‑ether backbone. If possible, perform a complementary analysis (e.g., NMR or GC‑MS) to resolve the structure when only limited FTIR data are available.