Table 2: Some peaks in FTIR spectra of TPU and TPU/MWCNT-Ns composites.

Possible assignmentsWavenumber (cm−1)
TPUTPU/MWCNT-NTPU/MWCNT-N
(H2O2)
TPU/MWCNT-N
(HNO3)
TPU/MWCNT-N
(KMnO4)

C=O stretch1759, 174417481759, 17431759
Free C=O stretch17281726171517231725
C=O stretch for hydrogen
bonded urethane group
1706 1710, 16901700, 16831708, 16891707, 1688
C=O stretch for hydrogen
bonded ester group
16621665165216641662
NH bending + C=C stretch 15971574157315741577
C–N stretch + N–H bending15311535153815391539