New biodegradable materials, with applications in packaging, can be obtained by plasticization of starch with glycerin and water. The physical properties of new materials are different from those of the initial components, and some properties of the initial components are subject to modifications during the synthesis process. Such modifications were investigated by XRD and IR spectroscopy. For this aim some new types of packaging materials with different starch, glycerin and water (mass %) ratios were prepared and investigated after extrusion process. XRD measurements indicate a progressive degradation of the ordered phase of the starch in function of glycerin and water content of samples. It can be observed that increasing of water concentration leads to a progressive degradation of the ordered structure of pure starch, (samples PI and P2), until a completely amorphous phase that appears at highest water concentration (sample P3 having starch/glycerin/ water 68/17/15 mass % ratio). These modifications can be correlated with the IR observations.
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