Journal
JOURNAL OF APPLIED POLYMER SCIENCE
Volume 81, Issue 12, Pages 3069-3082Publisher
JOHN WILEY & SONS INC
DOI: 10.1002/app.1758
Keywords
cornstarch; poly(lactic acid); gelatinization; thermal properties; mechanical properties
Categories
Ask authors/readers for more resources
Starch, a hydrophilic renewable polymer, has been used as a filler for environmentally friendly plastics for about 2 decades. Starch granules become swollen and gelatinized when water is added or when they are heated, and water is often used as a plasticizer to obtain desirable product properties. The objective of this research was to characterize blends from starch and poly(lactic acid) (PLA) in the presence of various water contents. The effects of processing procedures on the properties of the blends were also studied. Blends were prepared with a lab-scale twin-screw extruder, and tensile bars for mechanical testing were prepared with both compression and injection molding. Thermal and mechanical properties of the blends were analyzed, and the morphology and water absorption of the blends were evaluated. The initial moisture content (MC) of the starch had no significant effects on its mechanical properties but had a significant effect on the water absorption of the blends. The thermal and crystallization properties of PLA in the blend were not affected by MC. The blends prepared by compression molding had higher crystallinities than those prepared by injection molding. However, the blends prepared by injection molding had higher tensile strengths and elongations and lower water absorption values than those made by compression molding. The crystallinities of the blends increased greatly with annealing treatment at the PLA second crystallization temperature (155 degreesC). The decomposition of PLA indicated that PLA was slightly degraded in the presence of water under the processing temperatures used. (C) 2001 John Wiley & Sons, Inc.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available