Compositions including poly(hydroxyalkanoates) and graphene
A composite including poly(hydroxyalkanoate); and graphene. Also disclosed are methods of making articles.
1. A composite comprising:
poly(hydroxyalkanoate) (PHA); and
graphene, wherein said graphene comprises two-dimensional sheets and is atomically thick two-dimensional sheet composed of sp 2 carbon atoms arranged in a honeycomb structure.
2. The composite according to claim 1 , wherein the PHA is of formula (I)
where X can independently comprise carbon containing chains having from one to eleven carbons, and n can be an integer greater than about 10.
3. The composite according to claim 2 , wherein X can independently comprise carbon containing chains having from three to eleven carbons, and n can be an integer greater than about 10.
4. The composite according to claim 2 , wherein the PHA comprises short chain length poly(hydroxyalkanoates) (PHA SCL ).
5. The composite according to claim 2 , wherein the PHA comprises medium chain length poly(hydroxyalkanoates) (PHA MCL ).
6. The composite according to claim 5 , wherein the PHA MCL have a total chain length from six to fourteen.
7. The composite according to claim 2 , wherein X can independently comprise carbon containing chains of seven, five, three and one carbons.
8. The composite according to claim 2 , wherein X can independently comprise elements other than carbon and hydrogen.
9. The composite according to claim 1 , wherein the PHA is covalently crosslinked.
10. The composite according to claim 1 further comprising a second poly(hydroxyalkanoate).
11. The composite according to claim 1 , wherein there is not greater than about 10% by volume of graphene in the composite based on the total volume of the composite.
12. The composite according to claim 1 , wherein there is not greater than about 3% by volume of graphene in the composite based on the total volume of the composite.
13. The composite according to claim 1 , wherein the graphene is chemically modified.
14. The composite according to claim 1 further comprising filler materials.
15. A method of forming a composite comprising the steps:
obtaining graphene via thermal reduction of graphene oxide;
mixing poly(hydroxyalkanoate) (PHA) and the graphene to form a composite mixture;
forming an article from the composite mixture; and
initiating crosslinking.
16. The method according to claim 15 , wherein the composite mixture further comprises one or more solvents.
17. The method according to claim 16 , wherein the PHA is separately dissolved in a first solvent and the graphene is separately dispersed in a second solvent before they are combined to form a composite mixture, wherein the first and second solvent can be the same or different.
18. The method according to claim 17 , wherein the step of forming an article comprises evaporating at least a portion of the first and second solvent to form the article.
19. The method according to claim 18 , wherein the step of forming an article further comprises heating, compressing, or heating and compressing the article after at least a portion of the first and second solvent have been removed.
20. The method according to claim 15 , wherein initiating crosslinking occurs before the PHA and the graphene are mixed.
21. The method according to claim 15 , wherein the graphene comprises oxygen and has a carbon to oxygen ratio (C:O) from about 2:1 to about 1:0.
22. The method according to claim 21 , wherein the graphene has a high surface area to volume ratio.
23. A composite comprising:
poly(hydroxyalkanoate) (PHA); and
graphene, wherein said graphene comprises two-dimensional sheets and was formed by a top-down process.
24. The composite according to claim 23 , wherein the PHA is of formula (I)
where X can independently comprise carbon containing chains having from one to eleven carbons, and n can be an integer greater than about 10.
25. The composite according to claim 23 , wherein the PHA comprises short chain length poly(hydroxyalkanoates) (PHA SCL ).
26. The composite according to claim 23 , wherein the PHA comprises medium chain length poly(hydroxyalkanoates) (PHA MCL ) having a total chain length from six to fourteen.
27. The composite according to claim 23 , wherein the PHA is covalently crosslinked.
28. The composite according to claim 23 , wherein there is not greater than about 10% by volume of graphene in the composite based on the total volume of the composite.
29. The composite according to claim 23 , wherein the graphene is chemically modified.
30. The composite according to claim 23 further comprising filler materials.