How can you identify polyester from FTIR?

Quick answer

polyester 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 polyester, 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 6.1

  polyester

  Dalmau-Soler 等 - 2022 - Microplastics throughout a tap water supply networ DOI: 10.1111/wej.12766
• confidence 6.1

  polyester

  Fibers spreading worldwide: Microplastics and other anthropogenic litter in an Arctic freshwater lake DOI: 10.1016/j.scitotenv.2020.137904
• confidence 6.1

  polyester

  Microplastic and macroplastic ingestion by a deep diving, oceanic cetacean: The True's beaked whale Mesoplodon mirus DOI: 10.1016/j.envpol.2015.01.023
• confidence 4.9

  polyester

  Study of the effect of surface treatment of kenaf fiber on chemical structure and water absorption of kenaf filled unsaturated polyester composite DOI: 10.1088/1742-6596/908/1/012001
• confidence 4.9

  polyester

  Magnetic polyester bis-MPA dendron nanohybrid demulsifier can effectively break water-in-crude oil emulsions DOI: 10.1016/j.jmrt.2020.09.074
• confidence 4.9

  Polyester

  Effects of a Reactive Phosphorus–Sulfur Containing Flame-Retardant Monomer on the Flame Retardancy and Thermal and Mechanical Properties of Unsaturated Polyester Resin DOI: 10.3390/polym12071441
• confidence 4.9

  Polyester

  Self-Assembled Polyester Dendrimer/Cellulose Nanofibril Hydrogels with Extraordinary Antibacterial Activity DOI: 10.3390/pharmaceutics12121139
• confidence 4.9

  Polyester

  The Chitosan Implementation into Cotton and Polyester/Cotton Blend Fabrics DOI: 10.3390/ma13071616
• confidence 4.9

  Polyester

  Bio-Based Phosphate-Containing Polyester for Improvement of Fire Reaction in Wooden Particleboard DOI: 10.3390/polym15051093
• confidence 4.9

  Polyester

  Microstructure Changes in Polyester Polyurethane upon Thermal and Humid Aging DOI: 10.3390/polym8050197