POLYESTER
Entity identified- reference library comparison returns POLYESTER with high confidence (85 %) and a Top‑15 consensus pointing to aromatic/amide chemistry.
- The triad of peaks at 712, 875, and 1429 cm ¹ unequivocally indicates calcium carbonate filler, consistent with the strong similarity of calcium carbonate spectra appearing in the library’s Top‑15 candidates.
- Multiple independent literature sources assign these bands to carbonate vibrations, reinforcing the filler identification.
The carbonyl peak position (1797 cm ¹) is shifted relative to the most common polyester C=O absorption (~1720 cm ¹); this could be due to anhydride formation or electron‑withdrawing ester linkages, but does not rule out the polyester classification.