الفهرس 
Synthesis of some chitosan derivatives and their hybrid biomaterials
ABSTRACTOnly 14 pages are availabe for public view
 |  | from | 252 |  |  |
| | | from | 252 | | |
Abstract
First, five derivatives of chitosan Schiff bases were successfully synthesized by the condensation of 3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde with chitosan (Ch), also the reduced and quaternized forms of the Schiff base derivatives were prepared successfully. The reduction of crystallinity and thermal stability of the prepared chitosan Schiff bases compared with chitosan were characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TG). The activation energy of the decomposition was calculated using Coats{u2013}Redfern model. The adsorption of Congo Red (CR) and Maxilon Blue (MB) dyes onto chitosan and chitosan Schiff base derivatives were investigated. The results of antimicrobial activities indicated that the Schiff base derivatives and their reduced forms had excellent antimicrobial activities compared with chitosan. Second, biguanidinylated chitosan (ChG) and carboxymethyl chitosan (CMG) were successfully synthesized through the reaction of chitosan or carboxymethyl chitosan with cyanoguanidine. Glutaraldehyde cross-linked chitosan biguanidine (CChG) and carboxymethyl chitosan biguanidine (CCMG) and their silver nanocomposites (CChG/AgNPs and CCMG/AgNPs) were also prepared successfully. XRD data confirmed the presence of AgNPs with face-centered cubic (fcc) crystal structure.