Title The preparation of carboxymethyl chitosan hydrogel
Abstract
In alkaline conditions using chitosan and TCA make of carboxymethyl chitosan, and making glutaraldehyde (GA) as the crosslinker cross-link carboxymethyl chitosan for Carboxymethyl. Focusing on the conditions of chitosan and swelling of the hydrogel, PH sensitivity and various factors on swelling properties of carboxymethyl chitosan hydrogel, such as the impact of deacetylation carboxymethyl chitosan for swelling rate and the impact of crosslinker concentration for swelling rate of hydrogel. The results show that the preparation processing conditions of carboxymethyl chitosan: chitosan: sodium hydroxide: TCA (ratio) for the 1:5:2.5. The percentage of the quality concentration of Na0H is 50%, The chitosan is treated in low temperature of alkalization for 1-2 hours,and the reaction controlled in the 45 - 50 ℃ .The reaction time varies with the temperature, generally choosing about four hours, the product is white or pale yellow solid. In addition
the deacetylation of chitosan carboxymethyl and crosslinker amount of hydrogel are important factors for swelling rate of hydrogel.when the PH equai to 3.0, the hydrogel is shrinking, and when the pH equal to 1.0, 5.0, 7.4, 9.0 , hydrogel is swelling, and the swelling rate of gel in alkaline water conditions far greater than the ones under the acidic conditions .
