How can you identify PP from FTIR?

Quick answer

PP 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

Spectrum logic

The logic here is evidence aggregation: repeated literature mentions of PP, 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

• confidence 1.0

  PP

  Optical photothermal infrared spectroscopy with simultaneously acquired Raman spectroscopy for two-dimensional microplastic identification DOI: 10.1038/s41598-022-23318-2
• confidence 1.0

  PP

  Effect of Wood Fiber Loading on the Chemical and Thermo-Rheological Properties of Unrecycled and Recycled Wood-Polymer Composites DOI: 10.3390/app10248863
• confidence 0.9

  PP

  Simultaneous Treatment of Both Sides of the Polymer with a Conical-Shaped Atmospheric Pressure Plasma Jet DOI: 10.3390/polym15020461
• confidence 0.8

  PP

  Murphy 等 - 2022 - Assessment of microplastics in Irish river sedimen DOI: 10.1016/j.heliyon.2022.e09853
• confidence 0.6

  PP

  Birch 等 - 2021 - Isotope ratio mass spectrometry and spectroscopic DOI: 10.1016/j.talanta.2020.121743.
• confidence 0.5

  PP

  Nari 等 - 2021 - A comparative study on the thermal behaviour of PP DOI: 10.1016/j.matpr.2020.05.708
• confidence 0.5

  PP

  Kundu 等 - 2021 - Identification and removal of microand nano-plas DOI: 10.1016/j.cej.2021.129816.

• PP

  Biaxial Orientation Characterization in PE and PP Using WAXD X-Ray Pole Figures, FTIR Spectroscopy, and Birefringence DOI: 10.1177/8756087905056865

• PP

  Effects of Chlorinated Polypropylene on the Conformation of Polypropylene in Polypropylene/Chlorinated Polypropylene/Polyaniline Composites DOI: 10.1155/2015/317813

• PP

  Microplastic concentrations, size distribution, and polymer types in the surface waters of a northern European lake DOI: 10.1002/wer.1229