Abstract
Chitin, a natural polysaccharide, widely exists in the outer skeleton of arthropods such as shrimp. Chitin and its deacetylated
derivative chitosan have been reported to be useful for biomedical applications like wound healing ointments and dressings, drug
delivery system, and also shows several biological activities. It is predicted that chitosan will be one of the most demanding material
in 2005 and about 75% of chitosan will be used in biomedical areas as a key material.
In this study chitin and chitosan were prepared from shrimp shells in Iran for the first time and the degree of deacetylation was
estimated by analytical methods such as FT- IR and 1H- NMR.
Dilute HCl and then NaOH were mixed with shrimp shell powder in a proper condition in order to obtain chitin. Chitin was refluxed
in 30, 45 and 60% NaOH solutions for 1-3 h. The mixture was filtered and the residue washed with water and dried.
Chitin (1.5 g) obtained from the above procedure, and the chitosan yield was 60- 90%. One of the chitosan samples obtained in this
study was soluble that FT- IR and 1H- NMR determined the degree of deacetylation of this sample as 76 and 76.9% respectively.
We could reach to an easy and optimized method by changing the reaction time, reagents concentration and elimination of
decolorizing agent (decolorizing was done during the repetition of purification process) in process.
A relationship between the degree of deacetylation and solubility properties of chitosan was confirmed as other chitosan samples that
we obtained in this work could not be solved well and it needed to use other analytical devices such as solid NMR.
