• Top library match: EVA PE=1-9 #65

• A band at 1555 cm⁻¹ is attributed in literature to N–H bending (amide II) [5], a functional group absent in pure EVA; this band is not characteristic of the expected copolymer chemistry.
• The moderate band near 757 cm⁻¹ cannot be confidently assigned to a functional group that is typical of EVA; direct literature linking it to CF₂ bending is irrelevant to this polymer.
• The precise vinyl acetate content cannot be deduced from the FTIR spectrum alone; the library hit EVA PE=1-9 suggests a low proportion of vinyl acetate, but the actual ratio should be confirmed by an independent method.
• Weak or unexplained features such as the 1555 cm⁻¹ band could arise from a minor additive, residual processing aid, or surface contaminant, adding uncertainty to the purity assessment.

Recommended next steps: Perform quantitative analysis of the vinyl acetate content by hydrolysis and titration, NMR spectroscopy, or calibrated FTIR method. Use differential scanning calorimetry (DSC) to confirm the melting behavior and crystallinity of the polyethylene phase, verifying it is indeed a copolymer rather than a blend. If the 1555 cm⁻¹ band persists after purification, apply complementary techniques (e.g., Raman, XPS, or extraction) to identify possible amide‑containing additives or contaminants.