Semi Crystalline Behaviour of Cassava Starch Films Plasticized with Glycerol
In this work, the method of Fourier transform infrared was used to study the recrystallization phenomenon in cassava starch films containing different plasticizers content and type. The films were obtained by conventional casting method and then, conditioned for several periods in desiccators containing saturated water-NaBr solution and also, in desiccators containing silica gel. From the results, the main changes occurred in the fingerprint region, and were attributed to new interactions arising between the polymeric chains and the plasticizer. The changes in the peak amplitude located near 1015 cm-1 were associated to the formation of semi crystalline junctions in the film matrix, as affected by the plasticizer and moisture content in the films. The slight changes in peak positions were attributed to the modifications in the intermolecular forces in the film matrix. The semi crystallinity nature of films was checked by X-ray diffraction. At macroscopic scale, the flexibility of the films increased, which could favor the reorientation of the macromolecules.
Luís Guerra ROSA and Fernanda MARGARIDO
P. Bergo et al., "Semi Crystalline Behaviour of Cassava Starch Films Plasticized with Glycerol", Materials Science Forum, Vols. 636-637, pp. 745-752, 2010