Biodegradable polyester compositions with natural polymers and articles thereof
AssigneesThe United States of America as represented by the Secretary of Agriculture, Biotechnology Research and Development Corporation
InventorsJulious L. Willett, William M. Doane, Wayne Xu, Michael N. Mang, Jerry E. White
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Abstract
Compositions of the invention include a hydroxy-functional polyester and a natural polymer. Articles can be made from such a composition so as to have sufficiently strong tensile strengths as to form disposable utensils or to have sufficient stretchability so as to form thin wrap films. However, the compositions are more environmentally friendly than commodity plastics such as polyethylene or polystyrene. Granular starches derived from a grain, a root, a legume, or mixtures thereof, are particularly preferred as the natural polymers for inclusion in the compositions.
Claims13
A composition, useful for formed articles, comprising:
- a hydroxy-functional polyester wherein the hydroxy-functional polyester includes repeating units represented by Formula B:
- ##STR4## wherein each of R.sup.1 and R.sup.2 is individually a divalent organic moiety which is predominantly hydrocarbon, each R.sup.3 is individually hydrogen or lower alkyl, y is a fraction from 0 to 0.5 and x is a fraction from about 0.05 to about 0.4;
- and,
- granules of a natural polymer admixed with the polyester wherein the natural polymer granules are starch, a starch ester, a starch ether, a crosslinked starch, cellulose, or guar gum.
Dependencies are inferred from the claim text.