Thermal behavior of Schiff bases from chitosan

The thermal behavior of six biopolymeric Schiff bases obtained from the reaction of chitosan and salicylaldehyde derivatives is described. TG curves in air presented three events attributed to water loss, decomposition of the polysaccharide generating a carbonaceous residue that burns at higher temperatures. In N-2 similar results were observed, but the third event is not completed due to the absence of oxidant atmosphere. DSC curves in N-2 showed two events between room temperature and 500degreesC. The first was attributed to water loss, whereas the second is associated to the decomposition of the polysaccharide. Thermal analysis of biopolymeric Schiff bases showed that the decomposition temperature of C-N and C-MO samples increased with temperature which is in connection with the starting chitosan while the samples C-S, C-Br, C-Cl and C-ML started to decompose at similar temperatures compared to the non modified biopolymer.