What absorbs at 2829 cm⁻¹ in an FTIR spectrum?
A band near 2829 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 1 cited source
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Methyl | 1 | 1 | 1.0 |
| Methoxy (OCH3) | 1 | 1 | 1.0 |
| Methacrylate | 1 | 1 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| Acetate | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single authoritative rule. Always confirm against your sample context.
Literature behind these assignments
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Acetate confidence 1.0
“Other peaks in printed PLA include: the CH3 stretching vibrations at 2829 and 2932 cm-1 and OH stretching vibrations at 3501 and 3667 cm-1 due to the hygroscopic nature of PLA (although these features can also be attributed to the C=O overt”
Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure DOI: 10.3390/app7060579
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