Table 2 Vibrational band assignments for the ATR-FTIR spectra of the pale pink core and yellow surface of the SAYA mask

3674

ν O–H free

[23]

3350–3250

ν NH

[13, 19, 39, 59]

2966

νa C–H₃

[13, 15, 17,18,19, 38, 60]

2928

νa C–H₂

[13, 15, 17,18,19, 38, 60]

2870

νs C–H₃

[13, 15, 17,18,19, 38, 60]

1727

ν C=O

[13, 38, 56, 61]

1649

ν C=C in alkanes

[21, 62]

1600

ν C=C (benzene ring)

[13, 15, 17,18,19, 39, 56, 60, 61]

1580

ν C=C (benzene ring)

[13, 17, 18, 39, 56, 60, 61]

1530

δ O=C–N–H; ν O=C–N–H

[17,18,19, 39]

1454

δa C–H₃

[13, 17, 18, 38]

1373

δs C–H₃

[13, 17, 18, 38]

1345

ω C–H₂

[13, 17, 18]

1273

ν C–O

[60, 61]

1100

νa C–O–C Polyether-based polyol

[15, 18, 38, 39, 55]

1077 shoulder

ν C–O

[38, 39, 60, 61]

1039

Si–O

[23]

1015

Si–O

[23]

933

ρ C–H₃

[17, 18, 38]

744

ν C–H

[38, 39, 60, 61]

669

Amide V urethane seg

[37]