Material Properties and Glass Transition Temperatures of Different Thermoplastic Starches After Extrusion Processing

Abstract

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A high-resolution solid-state NMR study on starch–clay nanocomposites and the effect of aging on clay dispersion

“…[1][2][3] Thermoplastic starch has been produced using conventional thermal extrusion methods at suitable temperatures using added plasticizers (usually water and glycerol), and, in many cases, other polymer additives to modify the properties of starch-based materials. [4][5][6][7][8][9][10][11][12][13] Polymer-clay nanocomposites have attracted a great deal of interest by researchers in academia and industry, because significant improvements in many aspects of material performance can be obtained when using a very low dosing amount of such layered nanoparticles. [14][15][16][17][18][19] The property improvements of these doped materials compared with pure polymers or conventional micro-or macrocomposites are due to the significantly strengthened interfacial interactions between polymer chains and nanoparticles (layer thickness of the order of 1 nm, diameter of 30-1000 nm) when these particles are well dispersed in the polymer matrix.…”

Foaming of Polystyrene/ Thermoplastic Starch Blends

“…Its molecular weight must be low enough to easily penetrate the starch macromolecular network, but at the same time, its boiling point must be high enough to guarantee that it will not migrate or evaporate out of the material. Glycerol has been the most widely studied plasticizer for starch due to its high boiling point, availability, and low cost [1][2][3][4][5][6][7]. It was shown several years ago that extrusion at 150 C in a twin-screw extruder in the presence of a mixture of water and glycerol as plasticizers resulted in complete starch gelatinization.…”

Starch Protective Loose-Fill Foams

“…This temperature marks the transition from a highly flexible state to a glassy one. T g is considered the most important parameter for determining the mechanical properties of amorphous polymers and for the control of their crystallisation process (De Graaf et al, 2003).…”

“…The analysis of the influence of water on the T g of amylose and amylopectin showed that the very branched amylopectin had a slightly lower glass transition temperature than the amylose. On the grounds of published researches and practical observation it can be stated that starchy material containing water is generally in the glassy state and therefore brittle under natural conditions (De Graaf et al, 2003;Moates et al, 2001;Myllarinen et al, 2002).…”