Thermal and viscoelastic properties of some commercial starch products

Three commercial starch products for poly-olefins, marketed under the Mater-Bi, Cornplast, and Bioefect trademarks, were subjected to an accelerated soil burial test. Their thermal and viscoelastic behaviors were studied by differential scanning calorimetry (DSC) and dynamic mechanical spectroscopy. Degradation in soil leads to more significant changes both in the DSC thermogram and the mechanical relaxation spectrum of Mater-Bi. The relaxation spectra of Cornplast and Bioefect, two products containing polyethylene, basically coincide with that of pure low density polyethylene. The a-relaxation zone of these starch products is the most affected by the degradation process. (C) 2003 Wiley Periodicals, Inc.