Preparation and characterization of lobster shell chitosan:Modification of traditional method

摘要

Preparation of chitosan from lobster shells by Hackman method and modified Hackman method was compared with respect to their physico-chemical properties,molecular weight,degree of deacetylation,polydispersity and crystallinity.In modified method maximum yield (78%) of chitosan with almost 91% degree of deacetylation determined by first derivative UV spectra was achieved.Molecular size distribution as well as averag e size of chitosan produced by Hackman method was higher (PI 1.205,particle size 1448.6 nm) and of M_wt 10 X 10~5 when compared to chitosan produced by modified Hackman method (PI 0.8832,particle size 95.3 nm) of M_wt 3.98 X 10~5.X-ray powdered diffraction showed that chitosan prepared by Hackman method was found to be more crystalline,Bragg refractions 13.3 deg 2THETA (d=6.66 A) and 19.7 det 2THETA (d=4.51 A),respectively than chitosan produced by modified method,Bragg refraction 13.6 deg 2THETA (d =6.51 A).This method provides quality product in less time and is economical.