How can you identify PLA from FTIR?
This page summarizes the recurring FTIR evidence reported for PLA, including the most frequent peaks, supporting functional groups, and literature-backed interpretation patterns. It is a structured evidence page, not a claim of automatic single-spectrum certainty.
Backed by 25 cited sources
Quick answer
PLA is usually reported with a recurring pattern of peaks and functional-group evidence. The most useful approach is to cross-check at least two characteristic peaks before treating it as a match, then verify whether the full spectrum still fits the same material family.
Peak interpretation
Possible materials / groups
| Functional group | Evidence |
|---|---|
| Alkyl C-H | 39 |
| Methacrylate | 22 |
| Acetate | 22 |
| C-O single bond | 19 |
| Hydroxyl (O-H) | 19 |
| Carbonyl (C=O) | 18 |
| Methoxy (OCH3) | 16 |
| Carboxyl (COOH) | 14 |
Spectrum logic
The logic here is evidence aggregation: repeated literature mentions of PLA, repeated peak positions, and repeated functional-group associations. A strong material hypothesis should still be supported by multiple peaks that agree with each other, not by one headline band alone.
Real-world usage
This page is designed for polymer identification, incoming-material QC, unknown plastic analysis, recycled-content review, and literature-backed interpretation of reference spectra.
Common mistakes
- Calling a material match too early because one famous peak is present.
- Ignoring sample prep, fillers, oxidation, water, or additives that can change the apparent pattern.
- Using literature evidence without checking whether your own sampling mode and spectrum quality are comparable.
Verification advice
Use DSC, GC-MS, or TGA to validate the material hypothesis when the peak pattern is ambiguous or mixed.
Literature behind this page
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confidence 0.9
PLA
Development and Characterization of Commercial Biodegradable Films using Blown Film Extrusion Technology DOI: 10.18520/cs/v116/i6/997-1002 -
confidence 0.9
PLA
Magnesium Filled Polylactic Acid (PLA) Material for Filament Based 3D Printing DOI: 10.3390/ma12050719 -
confidence 0.9
PLA
Partial Polymer Blend for Fused Filament Fabrication with High Thermal Stability DOI: 10.3390/polym13193353 -
confidence 0.9
PLA
Mineralization of Poly(lactic acid) (PLA), Poly(3-hydroxybutyrate-co-valerate) (PHBV) and PLA/PHBV Blend in Compost and Soil Environments DOI: 10.7569/JRM.2016.634104 -
confidence 0.9
PLA
The Mechanical, Thermal, and Chemical Properties of PLA-Mg Filaments Produced via a Colloidal Route for Fused-Filament Fabrication DOI: 10.3390/polym14245414 -
confidence 0.9
PLA
Thermoanalytical characterization of clindamycin-loaded intravitreal implants prepared by hot melt extrusion DOI: 10.4103/2277-9175.161563 -
confidence 0.9
PLA
Polymer Composite Materials Based on Polylactide with a Shape Memory Effect for “Self-Fitting” Bone Implants DOI: 10.3390/polym13142367 -
confidence 0.8
PLA
Partial Biodegradable Blend with High Stability against Biodegradation for Fused Deposition Modeling DOI: 10.3390/polym14081541 -
confidence 0.8
PLA
Development of a Polymeric Membrane Impregnated with Poly-Lactic Acid (PLA) Nanoparticles Loaded with Red Propolis (RP) DOI: 10.3390/molecules27206959 -
confidence 0.7
PLA
Effect of lignin on mechanical, biodegradability, morphology, and thermal properties of polypropylene/polylactic acid/lignin biocomposite DOI: 10.1080/14658011.2018.1562746
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