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United States Department of Agriculture

Agricultural Research Service

Title: Extruded Cornstarch-Glycerol-Polyvinyl Alcohol Blends: Mechanical Properties, Morphology and Biodegradability

Authors
item Mao, Lijun - PLANET POLYMER, SAN DIEGO
item Imam, Syed
item Gordon, Sherald
item Cinelli, Patrizia - UNIV PISA/CHEM INDUST
item Chiellini, Emo - UNIV PISA/CHEM INDUST

Submitted to: Journal of Environment and Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2001
Publication Date: N/A

Interpretive Summary: Corn is produced in abundance in the U.S. Starch derived from corn is an excellent material for developing biodegradable single use consumer products. This report describes the extrusion of starch films along with other low cost compatible polymers such as glycerol and polyvinyl alcohol resulting in improved performance and biodegradable properties of extruded films. Utilization of corn byproducts will help add value to corn and will result in improved farm economy.

Technical Abstract: Cornstarch-glycerol-polyvinyl alcohol were blended, and extruded films were prepared. Elongation properties of extruded cornstarch films were improved by blending with glycerol. Further blending of starch-glycerol with poly-vinyl alcohol (PVOH) resulted in significant improvements in both tensile strength (TS) and percent elongation (%E). Furthermore, addition of PVOH in formulation improved mechanical property and moisture resistanc in films. The starch-glycerol-PVOH blends showed that decreases in glass transition temperatures (Tg's) were proportional to glycerol content. Scanning Electron Microscopy of fractured surfaces revealed numerous cracks in samples with less than 30% glycerol. Many starch granules were found exposed at the surface in the absence of PVOH. Starch-glycerol samples lost up to 70% of their dry weight within 22 days. Addition of PVOH slowed both the rate and extent of biodegradation.

Last Modified: 8/22/2014