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United States Department of Agriculture

Agricultural Research Service

Title: Biodegradation of Injection Molded Starch-Phbv Composite Blends in a Natural Compost Environment

item Imam, Syed
item Chen, Liang
item Gordon, Sherald
item Shogren, Randal
item Weisleder, David
item Greene, Richard

Submitted to: Pacific Basin Society Chemical International Congress Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 17, 1995
Publication Date: N/A

Technical Abstract: Injection molded composites were prepared by blending PHBV with 30% and 50% cornstarch. These composites were evaluated for their biodegradability in natural compost by measuring changes in their physical and chemical properties over a period of 125 days. The degradation of composite material, as evidenced by weight loss and deterioration in tensile properties, correlated with the amount of starch present in the samples (pure PHBV < 30% starch < 50% starch). Specifically, after 125 days exposure, pure PHBV exhibited a total weight loss of 7%. PHBV composites with 30% starch displayed a total weight loss of 28%, of which 19.3% was due to starch depletion and 8.7% was due to PHBV depletion. PHBV composites with 50% starch had a total weight loss of 55% , of which 34.7% was from starch and 20.3% was from PHBV. GPC analyses revealed a slight decrease in the Mw of residual PHBV. **1H proton NMR integration of branched -CH3 indicated similar rates of degradation for the PHB and PHV moieties of the copolymer.

Last Modified: 4/20/2015