SynopsisThe infrared spectra of wool heated in vacuum and in air to different temperatures ranging from 120 to 250°C were investigated. It was found that certain absorption bands disappear when wool is heated in vacuum to 180°C and in air to 120OC for 2 hr. Also, the results showed that the intensities of the C 4 stretching band at 1660 cm-', N-H stretching band at 3325 cm-I and the C-H stretching band at 2940 cm-I decrease when wool is heated in vacuum to 180°C and in air to 120°C. The spectra of the samples heated in vacuum to 25OOC and in air to 225°C exhibited strong absorption bands belonging to the carboxyl and sulfonate groups.