Abstract: Subcritical CH₂Cl₂ degreasing technology has shown good results in degreasing sheep skin. In order to explore the feasibility of this technology in the degreasing process of fur, thermogravimetric analysis, Fourier infrared spectroscopy, X-ray powder diffraction analysis, scanning electron microscopy and ultra-depth-of-field microscope observations were used to investigate the effects of temperature on thermal stability, macromolecular chain structure, aggregation state and surface morphology of wool fiber. The results showed that the thermal stability of wool fibers was improved when the temperature increased, and the molecular chain structure showed a changing trend from α -helix conformation to β -sheet conformation. When the temperature was above 39 ℃, the thermal stability was significantly improved, and partial S-S bonds of wool fiber were broken. When the temperature reached 41 ℃, most of the lipid substances on the surface of wool were removed with a slight damage to the scale layer.

Key words: wool fiber, subcritical solvent, degreasing, temperature, thermal stability