Thermal behaviour and interactions of cassava starch filled with glycerol plasticized polyvinyl alcohol blends

Thermal behaviour and interactions of glycerol plasticized polyvinyl alcohol (PVOH)-cassava starch (CSS) blended films were analysed using thermogravimetry and differential scanning calorimetry methods. The outcomes showed that addition of glycerol has reduced the onset and end-point melting temperatures of the blended films. Samples with 30 and 40 wt.% of PVOH-glycerol blended with CSS exhibited experimental enthalpy of melting (Delta H-m) lower than theoretical enthalpy of melting (Delta H-mi). Meanwhile, the thermogravimetry degradation of the PVOH-glycerol-cassava starch can be divided into three phases, whereby phase 1 is the vaporization of volatiles, phase 2 is the rapid decomposition/dehydration and elimination of degradants and phase 3 is the formation of carbonaceous residues. These samples have thermogravimetry degradation activation energy (E-a) higher than their original components. For instance. 20 wt.% of PVOH-glycerol blended with CSS has a E-a which is 6.36 and 4.07 times higher than glycerol plasticized PVOH and CSS, respectively. Blending of PVOH-glycerol and CSS are favorable to produce biodegradable compounds resist to thermal attacks. (C) 2010 Elsevier Ltd. All rights reserved.