• Top library match: Poly(1,4-butylene terephthalate) #28876

• The library confidence is low, with no numerical separation among candidates and all reported similarities at 0.000.
• No related-literature evidence was recovered to verify a specific polymer such as Poly(1,4-butylene terephthalate).
• The present peak list does not provide enough sample-specific distinguishing bands to safely separate one terephthalate polyester from other aromatic ester materials.
• A terephthalate-type polyester is plausible, but a firm entity-level assignment to Poly(1,4-butylene terephthalate) is not supported by the current evidence alone.
• The spectrum could also reflect another aromatic polyester or related benzoate-containing ester material within the same chemical direction.
• Key uncertainty remains because the result is driven mainly by a broad aromatic-ester library pattern rather than confirmed literature support.

Recommended next steps: Re-measure the FTIR spectrum with full spectral review, especially the 1600-1500 cm-1 aromatic ring region and the 1300-700 cm-1 fingerprint region, to look for terephthalate-specific band patterning. Compare the sample directly against authenticated spectra of Poly(1,4-butylene terephthalate), PET-type terephthalate polyesters, and isophthalate-containing polyesters. If the sample is a bulk solid or plastic, DSC can help test for a polyester such as PBT by checking for characteristic melting and crystallization behavior. If compositional confirmation is needed, pyrolysis-GC/MS or complementary Raman analysis would help distinguish a specific terephthalate polyester from other aromatic ester materials.