Submitted to: American Chemical Society Symposium Series
Publication Type: Proceedings
Publication Acceptance Date: 3/9/1996
Publication Date: N/A
Interpretive Summary: Corn is produced in surplus in the United States. Starch derived from corn is an excellent material for biodegradable plastics. However, to improve its strength and water barrier properties, starch must be blended with plasticizers. This report describes the use of polyvinyl alcohol as a low cost, biodegradable polymer for this purpose. A new method has been developed to prepare good quality starch-polyvinyl alcohol films bypassing the use of any plasticizers. Films prepared by this method display excellent biodegradation properties. This technology will utilize surplus corn for non-food applications which will help add value to corn and will result in improved farm economy.
Technical Abstract: Starch-polyvinyl alcohol (S-PVOH) cast films were prepared in the absence of plasticizers. Their physical and biodegradable properties were examined. Moisture absorption by the films was similar to that of PVOH at low humidity and increased linearly as the relative humidity increased. The tensile strength of the films decreased with increased humidity and did not display significant improvement with increased PVOH content. Higher PVOH content improved elongation when the relative humidity was 80% or higher. Biodegradation studies revealed that the presence of PVOH in the films slowed the rate of degradation.