Polybenzimidazole compounds, polymeric media, and methods of post-polymerization modifications
View Patent ↗A PBI compound includes imidazole nitrogens at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me 2 SiCH 2 — where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least 5 equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about 15.
1. A substituted PBI synthesis method comprising:
providing PBI having imidazole nitrogens;
reacting the PBI with an organic-inorganic hybrid compound that includes at least one element selected from the group consisting of metals, semi-metals, and phosphorous; and
substituting at least a portion of the imidazole nitrogens with an organic-inorganic hybrid moiety from the organic-inorganic hybrid compound.
2. The method of claim 1 wherein the PBI comprises poly-2,2′(m-phenylene)-5,5′-bibenzimidazole.
3. The method of claim 1 wherein the PBI is provided in a less than 5 wt % solution of the PBI in a solvent.
4. The method of claim 3 wherein the PBI is provided in an about 2.5 wt % solution of the PBI in a solvent.
5. The method of claim 1 further comprising ionizing the imidazole nitrogens before the reacting.
6. The method of claim 5 wherein the ionizing comprises deprotonating with an alkali hydride.
7. The method of claim 5 wherein the ionizing occurs at from about 20 to about 30° C.
8. The method of claim 5 wherein the ionizing occurs at about atmospheric pressure.
9. The method of claim 1 wherein the reacting and substituting occur at from about 20 to about 30° C.
10. The method of claim 1 wherein the reacting and substituting occur at about atmospheric pressure.
11. The method of claim 1 wherein the reacting uses at least 5 equivalents of the organic-inorganic hybrid compound in relation to the imidazole nitrogens to be substituted.
12. The method of claim 11 wherein the reacting uses about 15 equivalents of the organic-inorganic hybrid compound.
13. The method of claim 1 wherein substantially all of the imidazole nitrogens are substituted with the organic-inorganic hybrid moiety.
14. The method of claim 1 wherein the organic-inorganic hybrid compound comprises (R) n MR′X, wherein n is 1, 2, or 3, each R is independently selected from among alkyl, aryl, alkenyl, alkynyl, and oxide, M is metal, semimetal, or phosphorous, R′ is C 1 to C 20 alkyl, and X is Cl, Br, or I.
15. The method of claim 1 wherein the organic-inorganic hybrid compound comprises organohalosilane.
16. The method of claim 1 wherein the organic-inorganic hybrid compound comprises (R)Me 2 SiCH 2 Cl and R is selected from the group consisting of methyl, phenyl, vinyl, and allyl.
17. A substituted PBI synthesis method comprising:
providing PBI having imidazole nitrogens;
deprotonating the imidazole nitrogens at from about 20 to about 30° C. in a less than 5 wt % solution of the PBI in a solvent;
reacting the deprotonated PBI with (R)Me 2 SiCH 2 Cl at from about 20 to about 30° C., where R is selected from the group consisting of methyl, phenyl, vinyl, and allyl; and
substituting substantially all of the imidazole nitrogens with (R)Me 2 SiCH 2 —.
18. The method of claim 17 wherein the PBI comprises poly-2,2′(m-phenylene)-5,5′-bibenzimidazole.
19. The method of claim 18 wherein R is methyl.
20. The method of claim 18 wherein R is phenyl.
21. The method of claim 18 wherein R is vinyl.
22. The method of claim 18 wherein R is allyl.
23. A polymeric medium fabrication method comprising:
providing PBI having imidazole nitrogens;
reacting the PBI with an organic-inorganic hybrid compound that includes at least one element selected from the group consisting of metals, semi-metals, and phosphorous;
substituting at least a portion of the imidazole nitrogens with an organic-inorganic hybrid moiety from the organic-inorganic hybrid compound; and
forming a polymeric medium that comprises the substituted PBI.
24. The method of claim 23 wherein the polymeric medium comprises a separatory medium.
25. The method of claim 24 wherein the separatory medium exhibits an H 2 , Ar, N 2 , O 2 , CH 3 , or CO 2 gas permeability greater than the gas permeability of a comparable separatory medium instead comprising the PBI.
26. The method of claim 23 wherein the polymeric medium comprises an electronically conductive medium.
27. The method of claim 23 wherein the polymeric medium comprises an ionically conductive medium.
28. The method of claim 23 wherein the PBI comprises poly-2,2′(m-phenylene)-5,5′-bibenzimidazole.
29. The method of claim 23 further comprising deprotonating the imidazole nitrogens at from about 20 to about 30° C. in a less than 5 wt % solution of the PBI in a solvent.
30. The method of claim 23 wherein the reacting and substituting occur at from about 20 to about 30° C.
31. The method of claim 23 wherein the reacting uses at least 10 equivalents of the organic-inorganic hybrid compound in relation to the imidazole nitrogens to be substituted.
32. The method of claim 23 wherein substantially all of the imidazole nitrogens are substituted with the organic-inorganic hybrid moiety.
33. The method of claim 23 wherein the organic-inorganic hybrid compound comprises (R) n MR′X, wherein n is 1, 2, or 3, each R is independently selected from among alkyl, aryl, alkenyl, alkynyl, and oxide, M is metal, semimetal, or phosphorous, R′ is C 1 to C 20 alkyl, and X is Cl, Br, or I.
34. The method of claim 33 wherein M is selected from the group consisting of gallium, indium, silicon, germanium, tin, phosphorous, arsenic, and antimony.
35. The method of claim 23 wherein the organic-inorganic hybrid compound comprises organohalosilane.
36. The method of claim 23 wherein the organic-inorganic hybrid compound comprises (R)Me 2 SiCH 2 Cl and R is selected from the group consisting of methyl, phenyl, vinyl, and allyl.
37. The method of claim 23 wherein the substituted PBI exhibits a temperature marking an onset of decomposition that is greater than a value representing 80% of a temperature marking an onset of decomposition of the PBI.
38. A polymeric medium fabrication method comprising:
providing PBI having imidazole nitrogens;
deprotonating the imidazole nitrogens at from about 20 to about 30° C. in a less than 5 wt % solution of the PBI in a solvent;
reacting the deprotonated PBI with (R)Me 2 SiCH 2 Cl at from about 20 to about 30° C., where R is selected from the group consisting of methyl, phenyl, vinyl, and allyl;
substituting substantially all of the imidazole nitrogens with (R)Me 2 SiCH 2 —; and
forming a polymeric medium that comprises the substituted PBI.
39. The method of claim 38 wherein the polymeric medium comprises a separatory medium.
40. The method of claim 38 wherein the polymeric medium comprises an electronically conductive medium.
41. The method of claim 38 wherein the polymeric medium comprises an ionically conductive medium.
42. The method of claim 38 wherein the PBI comprises poly-2,2′(m-phenylene)-5,5′-bibenzimidazole.
43. The method of claim 42 wherein R is methyl.
44. The method of claim 42 wherein R is phenyl.
45. The method of claim 42 wherein R is vinyl.
46. The method of claim 42 wherein R is allyl.