Table 1 Summary of the main functional groups associated with weathered plastics in marine surface waters in this study65,66,67.
Functional group | Bond structure | Wavenumber (cm–1) | Weathering factor | Plastic type |
|---|---|---|---|---|
Hydroxyl | O − H | 3100−3700 | Surface oxidation, moisture | LLDPE, PP, ePS PET, PVC, PA, PCL |
Carbonyl | C = O | 1600–1800 | Surface oxidation, biogenic sources | LLDPE, PA, PCL |
Amide (I) | C = O with −NH2 | 1650–1580 | Biogenic sources | PP, PVC, PA, PCL |
Alkene, carbon double bond | C = C | 1600−1680 | Biogenic sources | LLDPE, PP, PVC, PA, PCL |
Amine (II) | −NHR | 1480−1580 | Biogenic sources | PVC, PA, PCL |
Amine (III) | −NHRR' | 1200−1280 | Biogenic sources | PVC, PA, PCL |
Carbon-oxygen | C − O | 1000−1200 | Surface oxidation, biogenic sources | LLDPE, PP, ePS, PVC, PCL |
Other (e.g., halogens) | e.g., C − F, −Cl, −Br, −I | 1150−500 | Ion adsorption | PP, ePS, PET, PVC, PA, |
