Infrared spectroscopic and thermal analysis of prepared cation exchangers from cellulosic materials

Different ion exchangers were prepared by incorporation of phosphate and sulfate groups onto acid- or alkali-treated wood pulp. The molecular structure of these ion exchangers are analyzed by infrared spectroscopy and the thermal gravimetric analysis technique. From infrared spectra, new bands are seen at wavenumbers 1200 and 980 cm−1 in phosphorylated wood pulp due to the formation of C–O–P bond. Other bands are seen at 1400, 1200 and 980 cm−1 in phosphosulfonated wood pulp due to the formation of C–O–P and C–O–S bonds. Also, infrared spectra show that the crystallinity index of acid-treated wood pulp has a higher value than untreated and alkali-treated wood pulps. On the other hand, the acid-treated and phosphorylated acid-treated wood pulps have higher activation energy than that in the case of untreated and phosphorylated alkali-treated wood pulps.