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Preparation and Characterization of Starch Acetate/Polyvinyl Alcohol Foams

The starch-based foam was preprared by moulding process and studied the effects on the density, mechanical properties, hardness and water absorption capacity of the foams with different polyvinyl alcohol (PVA) contents. The microstructure and crystallization of the foam was observed through the scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the addition of PVA could better improve the material mechanical properties, the elongation at break was increased from 15.72% to 113.86% while the hardness was reduced from 37.3 to 16.7. The density of foam reached to the minimum value of 0.261 g/cm3, attaining to the maximum tensile strength of 1.08 Mpa. SEM and XRD showed that the compatility of starch and PVA was very good and the addition of PVA helped to improve the bubble distribution of foam and inhibit the retrogradation of starch granules.