Comparative Study of Thermal Stability Using Natural Polymer Blend by Cross Linking

Chitin has wide range of applications as a biomaterial, but barriers still exist to its broader use due to its physical and chemical limitations. The present study evaluated the properties of polymeric blend films obtained from chitin and bentonite (Zeolite mineral) by the casting/solvent evaporation method. The cross linking agents formaldehyde and glutaraldehyde were incorporated into the polymer blends to improve the properties such as mechanical strength, tensile strength, surface hardness, stiffness, resistance to temperature and solvent attack. The structure and physical properties of the blend films were analysed by Fourier transform infra red spectroscopy (FTIR), thermogravimetric analysis (TGA), diferential scanning calorimetry (DSC) and wide angle XRD analysis. FTIR analyses confirmed that interactions were present between the hydroxyl groups of bentonite and amide group of chitin (lone pair of electrons available on nitrogen atom) in the blend films, while XRD studies shows that the films to exhibit an amorphous character. Thermogravimetric analyses showed that in the blend films, the thermal stability increased in the presence of crosslinking agent. The differential scanning calorimetry (DSC) studies revealed an endotherm corresponding to water evaporation around 100◦C in all the films and an exothermal, corresponding to the decomposition in the chitin side chain and blend films. The chitin-bentonite blend films exhibited a higher thermal stability in the presence of cross linking agents was found out.