Composites comprising rigid-rod polymers and graphene nanoparticles and process for making the same
The present invention relates to composites comprising rigid-rod polymers and graphene nanoparticles, processes for the preparation thereof, nanocomposite films and fibers comprising such composites and articles containing such nanocomposite films and fibers.
1. A polymer composite comprising a polymer and graphene nanoparticles dispersed in the polymer, the polymer comprising at least 50 wt % rigid rod polymer repeat units, wherein the graphene nanoparticles, on average, contain less than 25 planar graphene sheets in a stacked arrangement, and wherein the rigid rod polymer repeat units are derived from repeat units corresponding to Formula 1 or Formula 2
wherein the A 1 ring is a six-membered aromatic or a six-membered heterocyclic ring, Y is —O—,—S—or —NR′, R′ is hydrogen, hydrocarbyl, substituted hydrocarbyl or acyl, and X 1 and X 2 are independently a bond, para-ordered aryl or para-ordered heterocyclic ring.
2. The polymer composite of claim 1 wherein the A 1 ring is selected from the group consisting of
3. The polymer composite of claim 1 wherein at least 50 wt % of the polymer is derived from repeat units corresponding to Formula 1A, 1B, 1C, 1D, 2A, 2B, 2C or 2D
wherein Y, X 1 and X 2 are as defined in claim 1 .
4. The polymer composite of claim 1 wherein X 1 and X 2 are each a bond.
5. The polymer composite of claim 1 wherein X 1 is a bond and X 2 corresponds to Formula 3
wherein n is 0-4, each R 2 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, halo, phospho (—PO 3 H), or sulfo (—SO 3 H), and “*” designates the point of attachment of the A 2 ring system to the remainder of the repeat unit.
6. The polymer composite of claim 1 wherein X 1 is a bond and X 2 corresponds to Formula 3A, 3B or 3C
wherein n is 0-4, each R 2 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, halo, phospho (—PO 3 H), or sulfo (—SO 3 H), and “*” designates the point of attachment of the A 2 ring system to the remainder of the repeat unit.
7. The polymer composite of claim 3 wherein X 1 and X 2 independently correspond to Formula 3
wherein n is 0-4, each R 2 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, halo, phospho (—PO 3 H), or sulfo (—SO 3 H), and “*” designates the point of attachment of the A 2 ring system to the remainder of the repeat unit.
8. The polymer composite of claim 3 wherein X 1 is a bond and X 2 corresponds to Formula 3A, 3B or 3C
wherein n is 0-4, each R 2 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, halo, phospho (—PO 3 H), or sulfo (—SO 3 H), and “*” designates the point of attachment of the A 2 ring system to the remainder of the repeat unit.
9. The polymer composite of claim 1 wherein at least 50 wt % of the polymer is derived from repeat units corresponding to Formula 1I, 1J, 1K, 1L, 2I, 2J, 2K or 2L
wherein Y, R′, X 1 and X 2 are as defined in claim 1 .
10. The polymer composite of claim 9 wherein X 1 and X 2 independently correspond to Formula 3
wherein n is 0-4, each R 2 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, halo, phospho (—PO 3 H), or sulfo (—SO 3 H), and “*” designates the point of attachment of the A 2 ring system to the remainder of the repeat unit.
11. The polymer composite of claim 9 wherein X 1 is a bond and X 2 corresponds to Formula 3A, 3B or 3C
wherein n is 0-4, each R 2 is independently hydrogen, hydrocarbyl, substituted hydrocarbyl, hydroxy, halo, phospho (—PO 3 H), or sulfo (—SO 3 H), and “*” designates the point of attachment of the A 2 ring system to the remainder of the repeat unit.
12. The polymer composite of claim 9 wherein X 1 and X 2 are each a bond.
13. The polymer composite of claim 1 wherein at least 50 wt % of the polymer is derived from rigid rod ladder polymer repeat units corresponding to Formula 6
14. The polymer composite of claim 1 wherein graphene nanoparticles are present at a concentration in the range of about 5 wt % to about 50 wt % of the polymer composite.
15. The polymer composite of claim 1 wherein graphene nanoparticles are present at a concentration in the range of about 10 wt % to about 50 wt % of the polymer composite.
16. The polymer composite of claim 1 wherein the graphene nanoparticles contain on average less than 10 graphene sheets in a stacked arrangement.
17. The polymer composite of claim 1 wherein the tensile strength of the polymer composite is at least 50% greater than the tensile strength of the base polymer of the polymer composite.
18. The polymer composite of claim 1 wherein the tensile strength of the polymer composite is at least 100% greater than the elongation-to-break property of the base polymer of the polymer composite.
19. The polymer composite of claim 1 wherein the polymer comprised by the polymer composite has an average molecular weight of at least about 10,000.
20. The polymer composite of claim 1 wherein graphene nanoparticles are present at a concentration in the range of about 10 wt % to about 50 wt % of the polymer composite and at least 70 wt % of the polymer is derived from rigid rod polymer repeat units.
21. The polymer composite of claim 1 wherein at least 80 wt % % of the polymer is derived from rigid rod polymer repeat units or extended rod polymer repeat units.
22. The polymer composite of claim 1 wherein the rigid rod polymer contains repeat units selected from the group comprising benzobisazole, pyridobisimidazole, and benzamidazobenzo-phenanthroline.
23. The polymer composite of claim 1 wherein the polymer is a random copolymer.
24. The polymer composite of claim 1 wherein the polymer is a block copolymer.
25. The polymer composite comprising a polymer and graphene nanoparticles dispersed in the polymer, the polymer comprising at least 50 wt % rigid rod polymer repeat units, wherein the graphene nanoparticles, on average, contain less than 25 planar graphene sheets in a stacked arrangement, wherein polymer is a block copolymer comprising polymeric blocks corresponding to the following formulae
wherein Y and Z are the same or different and are selected from the group consisting of —O—, —S— and —NR′, R′ is hydrogen, hydrocarbyl, substituted hydrocarbyl or acyl; m is an integer that exceeds at least 50% of the number of repeat units in the polymer, and n is an integer.
26. The polymer composite of claim 1 further comprising repeat units of a non-extended/rigid rod polymer, the repeat units of the non-extended/rigid rod polymer constituting less than 25% of the repeat units of the polymer.
27. The polymer composite of claim 26 wherein the non-extended/rigid rod polymer is poly-paraphenylene terephthalamide.
28. A fiber comprising the composite of claim 1 .
29. A film comprising the composite of claim 1 .
30. An article comprising the fiber of claim 28 wherein the article is selected from the group consisting of tires, vehicle armor, bullet-proof vests, body armor and armor for a structure, an element of a ballistic protection system, or an element of a gas barrier layer of the hull for an airship.