Biodegradable starch-containing blend
AssigneeE. I. Du Pont de Nemours and Company
InventorsBarry Alan Morris, Edward J Stancik, Mark F Teasley
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Abstract
Disclosed is a composition comprising an aliphatic-aromatic copolyester consisting essentially of a dicarboxylic acid component that includes a terephthalic acid component and a linear aliphatic dicarboxylic acid component, a glycol component consisting essentially of a linear aliphatic glycol component and 0 to 4 mole percent based on 100 mole percent total glycol component of a dialkylene glycol component and at least one additional component; starch; water; and polyol plasticizer. Also described are shaped articles such as films which exhibit greater than expected tear strength and methods for preparing the films.
Claims16
A composition comprising, based on the weight of the composition, 40 to 70 weight % of an aliphatic-aromatic copolyester, 20 to 50 weight % of starch, 5 to 10 weight % of polyol plasticizer, and 0 to 10 weight % of water wherein
- the copolyester comprises a dicarboxylic acid component and a glycol component;
- the dicarboxylic acid component comprises, based on 100 mole % total acid component, about 80 to 40 mole % of a first aromatic dicarboxylic acid consisting essentially of a terephthalic acid component, about 10 to 60 mole percent of a linear aliphatic dicarboxylic acid component;
- and 0 to 30 mole percent of an additional dicarboxylic acid component;
- the additional dicarboxylic acid is selected from the group consisting of a second aromatic dicarboxylic acid, an alicyclic dicarboxylic acid, a branched dicarboxylic acid component, and combinations of two or more thereof;
- the glycol component consists essentially of, based on 100 mole percent total glycol component, about 100 to 60 mole percent of a linear aliphatic glycol component, 0 to about 4 mole percent of a dialkylene glycol component;
- and 0 to 40 mole percent of an additional glycol;
- the additional glycol component is selected from the group consisting of an alicyclic glycol component and a branched glycol component;
- the additional dicarboxylic acid component, the additional glycol component, and the branched hydroxy-carboxylic acid component is at least 2 mole % of the copolyester;
- and
- a film prepared from the composition has a tear strength measured in the machine direction at least 3 times greater than the tear strength measured in the machine direction of a film made from the copolyester.
Dependencies are inferred from the claim text.