Preparation and characterization of 1,2,4,5-benzenetetra carboxylic-chitosan
AbstractChemically cross-linked chitosan (MC) containing 1,2,4,5- benzenetetracarboxylic acid (BCA) as the cross-linking agent was prepared to improve the metal ions absorption capacity of native chitosan (NC) and limit its biodegradability. The Fourier transform infra-red (FTIR) and proton neutron magnetic resonance (1H NMR) results showed that BCA was successfully linked onto N-position of NC. The crystalline nature of NC was reduced significantly after cross-linking as examined by X-ray diffraction (XRD) analysis. Therefore, the glass transition temperature (Tg) of MC was higher than NC as reported by differential scanning calorimetry (DSC). Moreover, thermogravimetric (TGA) analysis showed that, MC had better thermal stability than NC. Morphology changes on the surface of NC and MC were characterized by field emission scanning electron microscopy (FESEM) and showed that MC had more porous surface than NC. In pH medium of 3 to 6, MC had excellent Cu (II) ions absorption capacity with a maximum 16 % higher than NC.