Composite materials with electrically conductive and delamination resistant properties

Patent metadata

Field	Value
Publication number	US-9908298-B2
Application number	US-201414560340-A
Country	US
Kind code	B2
Filing date	Dec 4, 2014
Priority date	Dec 13, 2013
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A curable composite material that may be used in applications where both high mechanical performance and high electrical conductivity are required. The curable composite material includes two or more layers of reinforcement fibers that have been infused or impregnated with a curable matrix resin and an interlaminar region containing carbon nanomaterials, e.g. carbon nanotubes, and insoluble polymeric toughening particles. The carbon nanomaterials are significantly smaller in size as compared to the polymeric toughening particles. The polymeric toughening particles are substantially insoluble in the matrix resin upon curing of the composite material, and remain as discreet particles at the interlaminar region after curing. Methods for fabricating curable composite materials and cured composite structures are also disclosed.

First claim

What is claimed is:

1. A curable composite material comprising:
at least two layers of reinforcing fibres impregnated with a curable matrix resin; and at least one interlaminar region formed between adjacent layers of reinforcing fibers, the interlaminar region comprising (i) carbon-based, nano-sized structures dispersed in a curable matrix resin, and (ii) insoluble polymeric toughening particles embedded in the same curable matrix resin,
wherein
the carbon-based, nano-sized structures have at least one dimension smaller than 100 nm (0.1 μm) and are the only conductive component in the interlaminar region,
the polymeric toughening particles have a mean particle size (d50) which is at least 100 times bigger than the smallest dimension of the carbon-based, nano-sized structures, and the mean particle size is within the range of 10-100 μm,
the polymeric toughening particles are insoluble in the matrix resin at the interlaminar region during curing of the composite material, and remain as discreet particles after curing, and
upon curing, the composite material exhibits electrical conductivity in the z-direction of greater than 1 S/m, Compression Strength After Impact (CAI), after impact at 30 J, of greater than 250 MPa as measured in accordance with ASTM7136/37, and interlaminar fracture toughness under mode I (G Ic ) of greater than 300 J/m 2 as measured in accordance to EN6033.

2. The curable composite material of claim 1 , wherein the toughening polymeric particles are dispersed in the interlaminar region at a content of 2% to 20% by weight based on the weight of the total matrix resin content in the composite material.

3. The curable composite material of claim 1 , wherein the carbon-based, nano-sized structures are present in an amount within the range 0.1% to 10% by weight based on the weight of the total matrix resin content in the composite material.

4. The curable composite material according to claim 1 , wherein the polymeric toughening particles are insoluble thermoplastic particles comprising at least one thermoplastic selected from the group consisting of: polyimide, polyamideimide, polyamide, polyphthalamide, polyetherketone, polyetheretherketone, polyetherketoneketone, polyaryletherketones, polyphenylenesulfide, liquid crystal polymers, copolymers thereof, and derivatives thereof.

5. The curable composite material according to claim 1 , wherein the insoluble polymeric toughening particles are insoluble elastomeric particles comprising at least one polymer or polymeric material selected from the group consisting of: cross-linked polybutadiene, polyacrylic, polyacrylonitrile, polystyrene, copolymers thereof, and derivatives thereof.

6. The curable composite material according to claim 1 , wherein the insoluble polymeric toughening particles are crosslinked particles, each particle comprising one of:
(a) a crosslinking network created by crosslinking a cross-linkable thermoplastic polymer having one or more one or more reactive groups with a cross-linking agent that is chemically reactive to the reactive groups, and
(b) an inter-penetrating polymer network (IPN) comprising thermoplastic polymer chains intertwined with an independent crosslinking network, wherein said IPN is created by reacting at least one compound having one or more reactive groups, a crosslinking agent that is chemically reactive to the reactive groups, and a thermoplastic polymer.

7. The curable composite material of claim 6 , wherein the crosslinked particles are crosslinked polyethersulfone-polyetherethersulfone (PES-PEES) particles.

8. The curable composite material according to claim 1 , wherein the carbon-based, nano-sized structures are selected from the group consisting of: carbon nano-tubes (CNTs), carbon nano-fibres, carbon nano-ropes, carbon nano-ribbons, carbon nano-fibrils, carbon nano-needles, carbon nano-sheets, carbon nano-rods, carbon nano-cones, and carbon nano-ohms, carbon black, graphite nano-platelets or nano-dots, graphenes, and combination thereof.

9. The curable composite material according to claim 1 , wherein the carbon-based, nano-sized structures are carbon nanotubes (CNTs).

10. The curable composite material of claim 9 , wherein the carbon nano-tubes (CNTs) have an aspect ratio from 50:1 to 5000:1.

11. The curable composite material according to claim 1 , wherein the carbon-based, nano-sized structures are multi-wall carbon nanotubes (MWCNTs).

12. The curable composite material according to claim 1 , wherein the insoluble polymeric toughening particles have an aspect ratio within the range of 5:1 to 1:1.

13. The curable composite material according to claim 1 , wherein the interlaminar region is free of any soluble thermoplastic particles that dissolve in the matrix resin upon curing.

14. The curable composite material according to claim 1 , wherein the toughening particles are substantially spherical and form a single layer of particles in the interlaminar region such that the interlaminar region has a depth that is defined by the diameters of the toughening particles.

15. The curable composite material according to claim 1 , wherein the curable matrix resin impregnating the reinforcing fibers and the curable matrix resin in the interlaminar region comprises one or more thermosetting resins which are common to both matrices.

16. The curable composite material according to claim 1 , wherein the curable matrix resin impregnating the reinforcing fibers is substantially the same as the curable matrix resin in the interlaminar region without the nano-sized structures and toughening particles.

17. The curable composite material according to claim 1 , wherein the curable matrix resin impregnating the reinforcing fibers and the curable matrix resin in the interlaminar region comprises uniformly dispersed carbon-based, nano-sized structures.

18. The curable composite material according to claim 1 , wherein the reinforcement fibers are carbon fibers.

19. The curable composite material according to claim 1 ,
wherein the polymeric toughening particles are substantially spherical in shape and the carbon-based, nano-sized structures are carbon nanotubes,
wherein the polymeric toughening particles have a mean particle size (d50) of at least 100 times greater than the diameter of the carbon nanotubes.

20. The curable composite material according to claim 1 , wherein the matrix resin is a thermosettable resin comprising epoxy or bismaleimide as a major component.

Assignees

• Cytec Ind Inc

Inventors

• Restuccia Carmelo Luca
• Lenzi Fiorenzo
• Frulloni Emiliano

Classifications

• B64D45/02

  Lightning protectors; Static dischargers · CPC title

• B32B2260/046

  Synthetic resin · CPC title

• B32B2260/021

  Fibrous or filamentary layer · CPC title

• C08J5/10

  characterised by the additives used in the polymer mixture · CPC title

• C08J2363/00

  Characterised by the use of epoxy resins; Derivatives of epoxy resins · CPC title