Improvement of Thermal Stability of Cassava Starch Films from the Incorparation of Bentonite Clay

Abstract

This study considered the effect of modified and unmodified bentonite clay on the thermal properties of films based on cassava starch. The bentonite clay was modified in the presence of cetyl trimethyl ammonium bromide (CTAB). The attainment of exfoliated or intercalated nanocomposite was characterized by X-ray diffraction (XRD) and Fourier transform by infrared radiation (FTIR). In XRD, it was verified that the cassava starch dispersed the modified clay in an exfoliated way and unmodified clay in an intercalated way. In the FTIR it was characterized that the cassava starch interacted more with the modified bentonite clay compared to unmodified. Finally, thermogravimetric curves showed the thermal property of the starch films concluding that the modified clay was the reinforcing material that contributed the most to the thermal stability of the cassava starch film, retarding its decomposition point, around 35oC , in relation to the pure starch film.