• Top library match: Poly(ethylenimine) #799

1. The FTIR search does not support a firm material identification. Although the nearest library entry is Poly(ethylenimine), all listed matches have zero similarity and the broader Top-15 pattern is chemically mixed. The observed spectrum is more safely described as an amine- and oxygen-containing organic polymer or polyol-like material, based on a broad band near 3287 cm⁻¹, strong fingerprint-region absorption at 1033 and 1241 cm⁻¹, C-H stretching at 2851 and 2919 cm⁻¹, and additional bands at 1509 and 1645 cm⁻¹ that are consistent with nitrogen-containing and/or hydrogen-bonded functionality. This supports a polar organic material containing C–N and/or C–O bonds, but not a defensible assignment to a specific library compound.

• All reported library similarities are 0.000, S-O the library hit order is not a reliable basis for a specific compound assignment.
• The Top-15 library set is internally inconsistent, spanning polyamines, polyols, sulfonated polymers, carbohydrates, and other unrelated materials.
• The library direction suggestion of methyl / sulfur heterocycle is not convincingly supported by the observed peak set, which does not show a clear sulfur-specific pattern.
• The present peak set does not provide characteristic bands that uniquely separate a polyamine from an oxygen-rich polymer or mixed hydrogen-bonded material.
• It remains unclear whether the broad 3287 cm⁻¹ feature is dominated by O–H, N–H, or both.
• The 1645 cm⁻¹ band could arise from bound water, amine-related deformation, or another non-unique contributor.
• The current evidence does not establish whether the sample is a single polymer, a modified polymer, or a formulation containing additives or moisture.

Recommended next steps: Re-run FTIR on a dried sample, or collect spectra before and after vacuum or mild thermal drying, to test whether the 3287 and 1645 cm⁻¹ bands are strongly influenced by absorbed water. Compare the sample directly against reference spectra for Poly(ethylenimine), poly(vinyl alcohol), and poly(ethylene oxide) collected under the same ATR or transmission conditions. Acquire complementary Raman spectroscopy to help distinguish amine-rich from alcohol/ether-rich polymer chemistry in the fingerprint region. If material confirmation is important, use elemental analysis or XPS to determine whether nitrogen is a major constituent; strong nitrogen content would favor a polyamine-type direction over a polyol/ether direction.