Abstract:Chitosan was ball milled by a planetary ball mill, and the effects of temperature and concentration of LiOH aqueous solution on the adsorption of chitosan in LiOH aqueous solution were studied and characterized by FT-IR spectra and XPRD spectra. The deacetylation degree of chitosan had no change, while the molecular weight of chitosan gradually declined during ball milling. Swelling degree of ball-milled chitosan in LiOH aqueous solution was all higher than that of the native chitosan in LiOH aqueous solution, which illustrated that ball milling treatment could promote the absorption of chitosan in LiOH aqueous solution. The solution temperature and concentration of LiOH aqueous solution had a significant influence on the swelling degree of chitosan and the swelling degree of ball-milled chitosan at 5 ℃ in 4.8wt% LiOH aqueous solution was the highest, which had no significant difference with swelling degree of chitosan in 4.8wt% LiOH solution by freezing-blasting. It illustrated that adsorption of ball-milled chitosan in low-temperature LiOH aqueous solution could also achieve the same effect of dissolution without tedious process of freezing-blasting. XPRD spectra and FT-IR spectra indicated that LiOH destroyed the crystal structure of chitosan and reacted with the acetyl and the hydroxyl groups of chitosan during the swelling process of LiOH solution.
