Glass transition temperature of thermoplastic starches

International Agrophysics (Impact Factor: 1.12). 01/2005; 19(3).
Source: DOAJ

ABSTRACT Thermoplastic starch was produced by mixing potato starch and glycerol in a single screw extruder. The glass transition temperatures of the materials obtained were measured by differential scanning calorimetry (DSC). Both the influence of extruder parameters and material parameters, such as moisture and glycerol content and amyloses/amylopectine ratio were investigated. Repeated extrusion cycles affect the glass transition temperature only to a very small extent.

324 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Environmental problems with conventional packaging materials developed the need of searching for new alternatives. Thermoplastic starch polymer (TPS) has been found to be a good source of raw materials for new packaging materials. In the paper changes of microstructure of TPS produced from different type of starch with glycerol content have been discussed. In general it can be stated that an increase of glycerol content in the mixture improves material structure quality.
    International Agrophysics 01/2006; · 1.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The expansion and puffing kinetics of commercial potato starch pellets were examined using a hot air fan oven in order to determine the puffing kinetics. The time for the onset of expansion showed uni-molecular type kinetic behaviour and was modelled by an Arrhenius plot. A pseudo-activation enthalpy for pellet expansion was also determined. The initial moisture content of the commercial pellets was controlled and the changes in the extent of puffing and the pseudo-activation enthalpy were found. The effect of type and quantity of cation in the formulation was then investigated. Expansion occurred even when no cation was added although the presence of cation did improve pellet expansion. The ratio of the native and pre-gelatinized starch in the pellets was also varied and showed to have limited effect on the extent of expansion. The puffing mechanism is discussed in light of these observations.
    Journal of Food Engineering 07/2011; 105(1):119-127. DOI:10.1016/j.jfoodeng.2011.02.014 · 2.77 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, increasing environmental concerns focused greater attention on the development of biodegradable materials. A thermoplastic starch derived from bioresources, sugar palm tree was successfully developed in the presence of biodegradable glycerol as a plasticizer. Sugar palm starch (SPS) was added with 15-40w/w% of glycerol to prepare workable bioplastics and coded as SPS/G15, SPS/G20, SPS/G30 and SPS/G40. The samples were characterized for thermal properties, mechanical properties and moisture absorption on exposure to humidity were evaluated. Morphological studies through scanning electron microscopy (SEM) were used to explain the observed mechanical properties. Generally, the addition of glycerol decrease the transition temperature of plasticized SPS. The mechanical properties of plasticized SPS increase with the increasing of glycerol but up to 30w/w%. Meanwhile, the water absorption of plasticized SPS decrease with increasing of glycerol.
    02/2013; 92(2):1711-6. DOI:10.1016/j.carbpol.2012.11.031
Show more


324 Reads