THERMAL STABILITY OF CHITOSAN NANOCOMPOSITES CONTAINING TIO2 AND ORGANO-MODIFIED MONTMORILLONITE

Abstract

The aim of this work was to investigate the effect of different nanoparticles (TiO2 and organically modified montmorillonite MMT) on thermal stability of chitosan thin films (obtained by casting) and to compare with previously studied- CuO and Ag effect. Thermal degradation was carried out in air atmosphere at 140°C up to 100 hours. Various functional groups of chitosan have a different susceptibility to degradation. The influence of nanoparticles amount on degradation of selected structural groups of chitosan was calculated. It was proved, that elongation at break of chitosan sample and its nanocomposites with TiO2 and organically modified montmorillonite decrease rapidly after 20h of thermal degradation. Moreover, as is clear from FTIR studies, that TiO2 nanoparticles enhance the resistant of the -C-O-C- bond responsible for chain scission of chitosan due to thermal degradation. An opposite effect is observed in a case of MMT, where the chain scission of -C-O-C- bond is higher than for pure chitosan. Another effect of nanoparticles are observed in destruction of unstable amine group (-NH3 band at 1560 cm -1 ) and formation of the amide group (band at 1650 cm -1 ). In this case both nanoadditives accelerate the decomposition of amine group and the formation of amide group in higher extent in comparison to pure chitosan.