摘要
The absorption behavior of chitosan in alkaline solution by freeze-blasting was studied.The influence of alkaline type,concentration,and small molecules was investigated,as well as the different roles of LiOH and NaOH in the absorption.Chitosan reached its maximum absorption rate when LiOH concentration was 4.8 wt%and NaOH 4.0 wt%,respectively.Chitosan showed better absorption capacity in LiOH solution.Urea could improve the absorption when its concentration was more than or equal to 4.0 wt%,and the improvement was greater in NaOH solution.Thiourea showed no obvious effect in LiOH solution,but showed an effect when NaOH concentration was 4.0 wt%and 6.0 wt%.During the absorption,NaOH only reacted with-OH of chitosan,while LiOH not only reacted with-OH of chitosan,but also reacted with the acetyl group of chitosan.LiOH was more powerful in destroying hydrogen bonding of chitosan.LiOH/urea solution may be a uniquely powerful solvent for chitosan.
