Methods of preparing polymer-organoclay composites and articles derived therefrom

1. A method for preparing a polymer-organoclay composite comprising:

combining a solvent and an unexfoliated organoclay to form a first mixture, wherein the organoclay comprises alternating inorganic silicate layers and organic layers, and has an initial spacing between the silicate layers, and further wherein the organoclay comprises a quaternary phosphonium or pyridinium cation of formula (2), formula (3), formula (4) or formula (5):

wherein Ar 1 , Ar 2 , Ar 3 and Ar 4 are independently C 6 -C 50 aromatic radicals; “a” is a number from 1 to about 200; “c” is a number from 0 to 3; R 1 is independently at each occurrence a halogen atom, a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, or a C 2 -C 20 aromatic radical; and R 2 is a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, a C 6 -C 50 aromatic radical, or a polymer chain,

wherein Ar 12 , Ar 13 , Ar 14 and Ar 15 are independently C 6 -C 50 aromatic radicals; and Ar 16 is a C 6 -C 200 aromatic radical, or a polymer chain comprising at least one aromatic group,

wherein Ar 6 , Ar 7 , and Ar 8 are independently C 6 -C 50 aromatic radicals; “b” is a number from 0 to 2; R 3 is independently at each occurrence a halogen atom, a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, or a C 2 -C 20 aromatic radical; and Ar 11 is a C 6 -C 200 aromatic radical, or a polymer chain comprising at least one aromatic group,

wherein Ar 6 , Ar 7 , and Ar 8 are independently C 6 -C 50 aromatic radicals; “b” is a number from 0 to 2; “d” is a number from 0 to 4; R 3 and R 4 are independently at each occurrence a halogen atom, a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, or a C 6 -C 20 aromatic radical; Z is a bond, a divalent C 1 -C 20 aliphatic radical, a divalent C 5 -C 20 cycloaliphatic radical, a divalent C 6 -C 20 aromatic radical, an oxygen linking group, a sulfur linking group, a SO 2 linking group, or a Se linking group; and Ar 9 is a C 10 -C 200 aromatic radical, or a polymer chain comprising at least one aromatic group;

exposing the first mixture to an energized condition of a sufficient intensity and duration to increase the initial spacing of the inorganic silicate layers, to form a second mixture;

contacting the first or second mixture with a polymer precursor;

polymerizing the polymer precursor to form a polymer, wherein the polymer is located in at least one region located between at least one pair of silicate layers, wherein the polymer is at least partially soluble in the solvent; and

removing at least a portion of the solvent from the second mixture, wherein the inorganic silicate layers remain separated by the polymer after removal of the solvent.

2. The method of claim 1 , wherein the polymerizing occurs at least partly during the exposing.

3. The method of claim 1 , wherein the polymerizing occurs at least partly after the exposing.

4. The method of claim 1 , wherein the polymerizing occurs at least partly during the removal of the solvent.

5. The method of claim 1 , wherein the polymer precursor is a polyamic acid.

6. The method of claim 1 , wherein the polymer precursor comprises a dianhydride component and a diamine component.

7. The method of claim 1 , wherein the energized condition is produced by a sonic energy source.

8. The method of claim 1 , wherein the energized condition is produced by a high shear mixer.

9. The method of claim 1 , wherein the energy is of sufficient intensity and duration to effect a net increase in the initial d-spacing of the organoclay.

10. The method of claim 1 , wherein the first mixture is exposed to an energized condition of sufficient intensity and duration to increase the initial spacing of the inorganic silicate layers by an amount from 5 Angstroms to 90 Angstroms.

11. The method of claim 1 , wherein the increase in the initial spacing of the inorganic silicate layers results in random spacing of the inorganic silicate layers.

12. The method of claim 1 , wherein the net increase in the initial d-spacing of the organoclay is from about 10 to about 500 percent.

13. A method for preparing a polymer-organoclay composite comprising:

combining a solvent, an unexfoliated organoclay, a dianhydride component, and a diamine component to form a first mixture, wherein the organoclay comprises alternating inorganic silicate layers and organic layers, and has an initial spacing between the silicate layers, and further wherein the organoclay comprises a quaternary phosphonium or pyridinium cation of formula (2), formula (3), formula (4) or formula (5):

wherein Ar 1 , Ar 2 , Ar 3 and Ar 4 are independently C 6 -C 50 aromatic radicals; “a” is a number from 1 to about 200; “c” is a number from 0 to 3; R 1 is independently at each occurrence a halogen atom, a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, or a C 2 -C 20 aromatic radical; and R 2 is a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, a C 6 -C 50 aromatic radical, or a polymer chain,

wherein Ar 12 , Ar 13 , Ar 14 and Ar 15 are independently C 6 -C 50 aromatic radicals; and Ar 16 is a C 6 -C 200 aromatic radical, or a polymer chain comprising at least one aromatic group,

wherein Ar 6 , Ar 7 , and Ar 8 are independently C 6 -C 50 aromatic radicals; “b” is a number from 0 to 2; R 3 is independently at each occurrence a halogen atom, a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, or a C 2 -C 20 aromatic radical; and Ar 11 is a C 6 -C 200 aromatic radical, or a polymer chain comprising at least one aromatic group,

wherein Ar 6 , Ar 7 , and Ar 8 are independently C 6 -C 50 aromatic radicals; “b” is a number from 0 to 2; “d” is a number from 0 to 4; R 3 and R 4 are independently at each occurrence a halogen atom, a C 1 -C 20 aliphatic radical, a C 5 -C 20 cycloaliphatic radical, or a C 6 -C 20 aromatic radical; Z is a bond, a divalent C 1 -C 20 aliphatic radical, a divalent C 5 -C 20 cycloaliphatic radical, a divalent C 6 -C 20 aromatic radical, an oxygen linking group, a sulfur linking group, a SO 2 linking group, or a Se linking group; and Ar 9 is a C 10 -C 200 aromatic radical, or a polymer chain comprising at least one aromatic group;

exposing the first mixture to an energized condition of a sufficient intensity and duration to increase the initial spacing of the inorganic silicate layers, to form a second mixture;

polymerizing the dianhydride component and the diamine component to form a polyamic acid; and

removing at least a portion of the solvent from the polyamic acid mixture to provide a polyimide, wherein the inorganic silicate layers remain separated by the polyimide after removal of the solvent.

14. The method of claim 13 , wherein the polymerizing occurs at least partly during the exposing.

15. The method of claim 13 , wherein the polymerizing occurs at least partly after the exposing.

16. The method of claim 13 , wherein the polymerizing occurs at least partly during the removal of the solvent.

17. The method of claim 13 , wherein the polymer precursor is a polyamic acid.

18. The method of claim 13 , wherein the polymer precursor comprises a dianhydride component and a diamine component.

19. The method of claim 13 , wherein the energized condition is produced by a sonic energy source.

20. The method of claim 13 , wherein the energized condition is produced by a high shear mixer.

21. The method of claim 13 , wherein the energy is of sufficient intensity and duration to effect a net increase in the initial d-spacing of the organoclay.

22. The method of claim 13 , wherein the first mixture is exposed to an energized condition of sufficient intensity and duration to increase the initial spacing of the inorganic silicate layers by an amount from 5 Angstroms to 90 Angstroms.

23. The method of claim 13 , wherein the increase in the initial spacing of the inorganic silicate layers results in random spacing of the inorganic silicate layers.

24. The method of claim 13 , wherein the net increase in the initial d-spacing of the organoclay is from about 10 to about 500 percent.