Research Information System
IRANIAN POLYMER JOURNAL, vol.24, no.6, pp.471-480, 2015 (SCI-Expanded)
The most plentiful natural biopolymer chitin and chitosan have become center of attraction of all party because of an unusual combination of biological activities, mechanical and physical properties. The several chemical modifications such as oligomerization, alkylation, quternization, enzymatic modifications, and graft copolymerization along with many assorted modifications have been carried out. However, its applications have only been shown in acidic medium because of its poor solubility in neutral and basic pH. In view of rapidly growing interest in chitosan its chemical aspects and chemical modification studies are reviewed. Four different aldehyde types, namely 4-hydroxybenzaldehyde (4HBA), 2-hydroxybenzaldehyde (2HBA), vanillin (VAN), 3-thiophenecarboxaldehyde (3TPCA), and their poly(4-hydroxybenzaldehyde) (P4HBA), poly(2-hydroxybenzaldehyde) (P2HBA), and poly (vanillin) (PVAN) were treated with chitosan to obtain Schiff base polymers. Although some of the chitosan-based Schiff bases were present in the literature, contrary to the literature the aldehydes (4HBA, VAN, 2HBA) were polymerized via oxidative polycondensation, followed by their reaction with chitosan to provide the Schiff base polymers, which were characterized by several techniques such as FTIR, TGA-DTA, DSC, SEM-EDX, and UV-Vis. Also, the solid-state electrical conductivities values of the compounds were measured by four-point probe technique.