AbstractThis study aims to investigate the degradation and stability of pulp treated in heterogeneous and homogeneous phases. The results showed that the homogeneous system 1-Allyl-3-Hexylimidazolium chloride (AHIMCl) ionic liquid exhibited special dissolubility for pulp samples, but showed lower thermal stability than the heterogeneous treatments by 20 wt% NaOH or 2-ethanediamine (EDA) solution. Compared with the 20 wt% NaOH solution, the 20 wt% EDA solution and AHIMCl treatments had special decrystallizing ability, and the 20 wt% EDA solution had lower reductions in the mean degree of polymerization of pulp after the treatments for 72 h at 5 oC. X-ray diffractogram (XRD) analysis showed that after the AHIMCl and 20 wt% EDA solution treatments, the 002 crystal plane size of the treated pulp samples (＜1 nm) became much lower than that of the raw pulp (5.09 nm). The diffracted intensity indicating 101 crystal planes nearly disappeared from the XRD curve of AHIMCl treated pulp samples. The X-ray photoelectron spectroscopy (XPS) analysis indicated that the significant reduction in C1s2 and O1s2 contents of the regenerated samples after the AHIMCl treatment implies that AHIMCl severely destroy the in crystalline and amorphous regions.