CHARACTERIZING ESTER CROSSLINKAGES IN COTTON CELLULOSE WITH FT-IR PHOTOACOUSTIC-SPECTROSCOPY

Polycarboxylic acids are being developed as new nonformaldehyde finishes for cotton fabrics to replace the traditional dimethyloldihydroxylethyleneurea. In this research, Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS) was used to characterize the intermolecular ester crosslinkages in cotton cellulose. When esterification occurs between a polycarboxylic acid and cotton cellulose, the carbonyls retained in the cotton exist in three forms: ester, carboxylic acid, and carboxylate anion. The FT-IR data show that the band of the ester carbonyl can be separated from the bands of the other two carbonyls; therefore, the ester crosslinkages of the finished cotton fabrics can be compared on a semiquantitative basis with FT-IR spectroscopy. FT-IR/PAS was used to study the hydrolysis of the ester linkages, the recurability of the finished cotton fabrics, and the distribution of ester crosslinkages between the surfaces of the cotton fabrics and their interiors.