Covalent conjugates of graphene nanoparticles and polymer chains and composite materials formed therefrom

Patent metadata

Field	Value
Publication number	US-11479652-B2
Application number	US-201916596303-A
Country	US
Kind code	B2
Filing date	Oct 8, 2019
Priority date	Oct 19, 2012
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

A method for forming a graphene-reinforced polymer matrix composite is disclosed. The method includes distributing graphite microparticles into a molten thermoplastic polymer phase; and applying a succession of shear strain events to the molten polymer phase so that the molten polymer phase exfoliates the graphite successively with each event until at least 50% of the graphite is exfoliated to form a distribution in the molten polymer phase of single- and multi-layer graphene nanoparticles less than 50 nanometers thick along the c-axis direction.

First claim

What is claimed is:

1. A method for forming a graphene-reinforced polymer matrix composite, comprising:
(a) distributing graphite microparticles into a molten thermoplastic polymer phase, wherein at least 50% by weight of graphite in the graphite microparticles comprises multilayer graphite crystals between 1.0 and 1000 microns thick along a c-axis direction;
(b) applying a succession of shear strain events to the molten polymer phase so that the shear stress within the molten polymer phase is equal to or greater than the Interlayer Shear Strength (ISS) of the graphite microparticles and the molten polymer phase mechanically exfoliates the graphite successively with each event until the graphite is at least partially exfoliated to form a distribution in the molten polymer phase of essentially pure and uncontaminated single- and multi-layer graphene nanoparticles less than 10 nanometers thick along the c-axis direction; and
(c) continuing the shear strain events until graphene fractures of the exfoliated single- and/or multi-layer graphene nanoparticles are formed across the basal plane defined by a-axis and b-axis, wherein the edges of the graphene fractures comprise reactive free radical graphenic carbon bonding sites that react with the one or more molten thermoplastic polymers to provide a composite where thermoplastic polymer chains are directly covalently bonded to, and inter-molecularly cross-linked by, the single- and/or multi-layer graphene nanoparticles.

2. The method of claim 1 , wherein the composite comprises from about 0.01 wt % to about 90 wt % of particles selected from the group consisting of single- and multi-layer graphene nanoparticles less than 10 nanometers thick along a c-axis direction, partially exfoliated multi-layer graphene nanoparticles from 10 to 1,000 nanometers thick along the c-axis direction, graphite microparticles, and combinations of two or more thereof, wherein from about 5 wt % to less than about 95 wt % of the particles are single- and multi-layer graphene nanoparticles less than 10 nanometers thick along the c-axis direction.

3. The method of claim 2 , wherein the composite comprises from about 0.01 wt % to about 60 wt % of the single- and multi-layer graphene nanoparticles.

4. The method of claim 2 , wherein the composite comprises from about 0.01 wt % to about 30 wt % of single- and multi-layer graphene nanoparticles.

5. The method of claim 1 , wherein the composite comprises at least one thermoplastic polymer molecule bonded or adhered to one or more mechanically exfoliated single- or multi-layer graphene nanoparticles.

6. The method of claim 1 , wherein the composite comprises at least one single- or multi-layer graphene nanoparticle covalently bonded to one or more thermoplastic polymer molecules.

7. The method of claim 1 , wherein the composite comprises a distribution of a plurality of graphene/polymer clusters, wherein each of the graphene/polymer clusters comprises at least one thermoplastic polymer molecule covalently bonded or adhered to one or more mechanically exfoliated single- or multi-layer graphene nanoparticles.

8. The method of claim 1 , wherein the composite comprises a distribution of a plurality of graphene/polymer clusters, wherein each of the graphene/polymer clusters comprises at least one single- or multi-layer graphene nanoparticle covalently bonded to one or more thermoplastic polymer molecules.

9. The method of claim 1 , wherein the step of applying a succession of shear strain events comprises applying a succession of shear strain events to generate a shear rate less than or equal to 1000 sec-1.

10. The method of claim 1 , wherein the polymer is selected from the group consisting of acrylics, polyamide-imide (PAI), polyetherimide (PEI), polyimide (PI), aromatic thermoplastic polyester, polycarbonate (PC), Polybutadiene (PBD), polydimethylsiloxane (PDMS), polyaryletherketone (PAEK), polyethylene naphthalene dicarboxylate (PEN), polysulphone (PSU, polyphenylene sulfide (PPS), polyethylene), polyglycolic acid (PGA), polylactic acid (PLA), polylactic-glycolic acid copolymer (PLGA), polyoxymethylene plastic (POM/Acetal), polyphenylene ether (PPE or PPO), polypropylene (PP), polystyrene (PS), polytetrafluoroethylene (PTFE/TEFLON), polyvinylchloride (PVC), polyvinylidene fluoride (PVDF), thermoplastic elastomer (TPE), liquid crystal polymer, natural or synthetic rubber, polyamide (PA), and the mixtures of two or more thereof.

11. The method of claim 10 , wherein the polyamide is selected from the group consisting of polyamide-11 (nylon-11), polyamide-12 (nylon-12), polyamide-4,6 (nylon-4,6), polyamide-6 (nylon-6), polyamide-6,10 (nylon-6,10), polyamide-6,12 (nylon-6,12), polyamide-6,6 (nylon-6,6), polyamide-6,9 (nylon-6,9).

12. The method of claim 1 , wherein the graphite is doped with other elements to modify a surface chemistry of the exfoliated graphene nanoparticles.

13. The method of claim 1 , wherein a surface chemistry or nanostructure of the dispersed graphite is modified to enhance bond strength with the polymer matrix to increase strength and stiffness of the composite.

14. The method of claim 1 , wherein the graphene nanoparticles are directionally aligned thereby providing one-, two- or three-dimensional reinforcement of the polymer phase.

15. The method of claim 1 , wherein the composite comprises residual graphite microparticles.

16. A graphene-reinforced polymer matrix composite comprising: a distribution in a thermoplastic polymer matrix of single- and multi-layer graphene nanoparticles less than 50 nanometers thick along a c-axis direction and graphite microparticles, wherein composite comprises thermoplastic polymer chains inter-molecularly cross-linked by mechanically torn single- and/or multi-layer graphene nanoparticles having carbon atoms with reactive bonding sites on the torn edges of the graphene nanoparticles.

17. The composite of claim 16 , comprising: (i) at least one thermoplastic polymer molecule covalently bonded or adhered to one or more mechanically exfoliated single- or multi-layer graphene nanoparticles; or (ii) at least one single- or multi-layer graphene nanoparticle covalently bonded to one or more thermoplastic polymer molecules.

18. The composite of claim 16 , comprising a distribution of a plurality of graphene/polymer clusters, wherein each of the graphene/polymer clusters comprises at least one thermoplastic polymer molecule covalently bonded or adhered to one or more mechanically exfoliated single- or multi-layer graphene nanoparticles.

19. The composite of claim 16 , comprising from about 0.01 wt % to about 90 wt % of particles selected from the group consisting of single- and multi-layer graphene nanoparticles less than 10 nanometers thick along a c-axis direction, partially exfoliated multi-layer graphene nanoparticles from 10 to 1,000 nanometers thick along the c-axis direction, graphite microparticles, and combinations of two or more thereof, wherein from about 5 wt % to less than about 95 wt % of the particles are single- and multi-layer graphene nanoparticles less than 10 nanometers thick along the c-axis direction.

Assignees

• Univ Rutgers

Inventors

• Nosker Thomas J
• Lynch-Branzoi Jennifer K
• Hendrix Justin W
• Kear Bernard H
• Chiu Gordon
• Tse Stephen

Classifications

• C08K3/04 Primary

  Carbon · CPC title

• C08J2381/06

  Polysulfones; Polyethersulfones · CPC title

• C08J2300/22

  Thermoplastic resins · CPC title

• B29K2105/162

  Nanoparticles · CPC title

• B29C48/67

  having incorporated mixing devices not provided for in groups B29C48/52 - B29C48/66 · CPC title