TY - JOUR
T1 - Acetylated starch-polylactic acid loose-fill packaging materials
AU - Guan, Junjie
AU - Eskridge, Kent M.
AU - Hanna, Milford A.
N1 - Funding Information:
This research was done in part, with funding from the Agricultural Research Division of the Institute of Agriculture and Natural Resources and the Nebraska Research Initiative as part of a project on “materials from the biosphere.”
PY - 2005/9
Y1 - 2005/9
N2 - Different genetic and botanical sources of starches are available for use in hydrophobic starch-based packaging materials. The objectives of this study were to evaluate the effects of the type of acetylated starch and the presence of polylactic acid (PLA) and ethanol on the functional properties of extruded foams, and to compare the specific mechanical energy requirements for preparing these foams. Acetylated starches prepared from potato and native (25% amylose) and high amylose (70%) corn starches were extruded with 0, 7.5, or 15% PLA and 8, 13, or 18% ethanol using a twin-screw extruder with a 160°C barrel temperature and 180 rpm screw speed. Response surface methodology was employed to study the acetylated starch, PLA, and ethanol effects on radial expansion ratio, bulk density and compressibility of the extruded foams and the specific mechanical energy required to extrude the acetylated starch-PLA blends. The acetylated potato and native and high amylose corn starches had degrees of substitution (DS) of 1.09, 2.05, and 2.65, respectively. Acetylated 70% amylose cornstarch agglomerates had the highest hardness whereas acetylated potato starch had the lowest. Higher DS acetylated starch had higher radial expansion ratio, compressibility, specific mechanical energy requirement, and lower bulk density than acetylated starch-PLA foam. Ethanol functioned as a blowing agent to expand the foams and as a solubilizing agent to depolymerize the PLA and starch to form a homogeneous dough. Foam expansion increased with addition of PLA.
AB - Different genetic and botanical sources of starches are available for use in hydrophobic starch-based packaging materials. The objectives of this study were to evaluate the effects of the type of acetylated starch and the presence of polylactic acid (PLA) and ethanol on the functional properties of extruded foams, and to compare the specific mechanical energy requirements for preparing these foams. Acetylated starches prepared from potato and native (25% amylose) and high amylose (70%) corn starches were extruded with 0, 7.5, or 15% PLA and 8, 13, or 18% ethanol using a twin-screw extruder with a 160°C barrel temperature and 180 rpm screw speed. Response surface methodology was employed to study the acetylated starch, PLA, and ethanol effects on radial expansion ratio, bulk density and compressibility of the extruded foams and the specific mechanical energy required to extrude the acetylated starch-PLA blends. The acetylated potato and native and high amylose corn starches had degrees of substitution (DS) of 1.09, 2.05, and 2.65, respectively. Acetylated 70% amylose cornstarch agglomerates had the highest hardness whereas acetylated potato starch had the lowest. Higher DS acetylated starch had higher radial expansion ratio, compressibility, specific mechanical energy requirement, and lower bulk density than acetylated starch-PLA foam. Ethanol functioned as a blowing agent to expand the foams and as a solubilizing agent to depolymerize the PLA and starch to form a homogeneous dough. Foam expansion increased with addition of PLA.
KW - Acetylated starch
KW - Extrusion
KW - Polylactic acid
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U2 - 10.1016/j.indcrop.2004.06.004
DO - 10.1016/j.indcrop.2004.06.004
M3 - Article
AN - SCOPUS:22544433482
SN - 0926-6690
VL - 22
SP - 109
EP - 123
JO - Industrial Crops and Products
JF - Industrial Crops and Products
IS - 2
ER -