Identification of cellulose nitrate based adhesive repairs in archaeological pottery of the University of Melbourne’s Middle Eastern archaeological pottery collection using portable FTIR-ATR spectroscopy and PCA

Heritage Science

Table 4 Characteristic FTIR-ATR absorption bands of primary polymers in control adhesive samples

Primary polymer	Region [38] (cm⁻¹)	Control peaks (cm⁻¹)^a	Vibration mode [6, 26, 37, 38, 40]	Functional group [6, 26, 37, 38, 40]
CN	1660–1625	1638	Asymmetric stretch	NO₂
	1285–1270	1272	Symmetric stretch	NO₂
	890–800	822	Stretch	N–O
Acrylic	1740–1640	1721	Stretch	C=O
	1300–900	1235	Stretch	C–O
	1300–900	1140	Rocking vibration	CH₃
PVAc	1750–1650	1729	Symmetric stretch	C=O
	1300–900	1225	Stretch	C–O
	1300–900	1018	Stretch	C–O (CH–O)
Protein	1660–1600	1630	Amide I (stretch, bend)	C=O, minor N–H and C–N
	1565–1500	1536	Amide II (bend, stretch)	N–H, C–N
	1480–1300	1450	Amide III (stretch, bend)	C–N, N–H