Polymer nanoparticles for controlling permeability and fiber volume fraction in composites

Patent metadata

Field	Value
Publication number	US-10160840-B2
Application number	US-201414493368-A
Country	US
Kind code	B2
Filing date	Sep 23, 2014
Priority date	Sep 23, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A fiber tow may include a plurality of reinforcing filaments each having a filament cross-sectional width. At least a portion of the polymer nanoparticles may be coupled to at least one of the reinforcing filaments and/or to other polymer nanoparticles. The polymer nanoparticles may have a particle cross-sectional width that is less than the reinforcing filament cross-sectional width. The polymer nanoparticles may provide a local filament spacing between the reinforcing filaments to reduce or avoid direct contact between reinforcing filaments, to allow for resin flow between the filaments, and/or to meet fiber volume fraction requirements.

First claim

What is claimed is:

1. A fiber tow for embedding in a resin, comprising:
a plurality of reinforcing filaments each having a filament cross-sectional width;
a plurality of polymer nanoparticles;
the polymer nanoparticles having a particle cross-sectional width that is less than the filament cross-sectional width;
at least some of the polymer nanoparticles are directly and independently coupled to at least one of the reinforcing filaments and/or to other polymer nanoparticles prior to one of pre-pregging or resin infusion of the fiber tow;
the polymer nanoparticles being located in spaced relation to each other on the at least one of the reinforcing elements;
the polymer nanoparticles having a material composition configured to remain in a solid state below a cure temperature of the resin, and dissolve in the resin as a result of the temperature of the polymer nanoparticles reaching the cure temperature of the resin; and
the reinforcing filaments being spaced apart at the local filament spacing via the polymer nanoparticles prior to and during one of pre-pregging or resin infusion.

2. The fiber tow of claim 1 , wherein:
the plurality of reinforcing filaments include a first filament and a second filament;
the plurality of polymer nanoparticles include a first polymer nanoparticle coupled to the first filament and a second polymer nanoparticle coupled to the second filament; and
the first polymer nanoparticle contacting the second filament and/or the second polymer nanoparticle.

3. The fiber tow of claim 1 , wherein:
the polymer nanoparticles have a particle cross-sectional width of 10-200 nanometers.

4. The fiber tow of claim 1 , wherein:
the polymer nanoparticles are generally spherical.

5. The fiber tow of claim 1 , wherein:
the polymer nanoparticles are formed of thermoplastic material comprising at least one of the following: acrylics, fluorocarbons, polyamides, polyolefins, polyethylenes, polyesters, polycarbonates, polypropylenes, polyurethanes, polyaryletherketones, polyetherimides, polyethersulfone, polysulfone, and polyphenylsulfone;
the resin is formed of thermosetting material comprising at least one of the following: polyurethanes, phenolics, polyimides, sulphonated polymer (polyphenylene sulphide), a conductive polymer (e.g., polyaniline), benzoxazines, bismaleimides, cyanate esthers, polyesters, epoxies, thiols, and silsesquioxanes.

6. The fiber tow of claim 1 , wherein:
at least a portion of the polymer nanoparticles are core-sheath nanoparticles additionally comprising a sheath encapsulating a core, the sheath being formed of a different material than the core; and
the sheath being coupled to at least one reinforcing filament.

7. The fiber tow of claim 6 , wherein:
the sheath is formed of thermoplastic material that is configured to melt-fuse to the reinforcing filament as a result of a temperature of the sheath reaching a glass transition temperature of the sheath.

8. A composition, comprising:
a resin; and
a plurality of fiber tows embedded in the resin, one or more of the fiber tows including a plurality of reinforcing filaments, each reinforcing filament having a filament cross-sectional width;
a plurality of polymer nanoparticles coupled to the reinforcing filaments, at least some of the polymer nanoparticles being directly and independently coupled to at least some of the reinforcing filaments and/or to other polymer nanoparticles prior to one of pre-pregging or resin infusion of the fiber tows, the polymer nanoparticles being located in spaced relation to each other on at least one of the reinforcing elements;
the polymer nanoparticles having a particle cross-sectional width that is less than the filament cross-sectional width; and
the polymer nanoparticles having a material composition configured to remain in a solid state below a cure temperature of the resin, and being configured to dissolve in the resin as a result of the temperature of the polymer nanoparticles reaching the cure temperature of the resin; and
the reinforcing filaments being spaced apart at the local filament spacing via the polymer nanoparticles prior to and during one of pre-pregging or resin infusion.

9. The composition of claim 8 , wherein:
the polymer nanoparticles have a particle cross-sectional width of 10-200 nanometers.

10. The composition of claim 8 , wherein:
at least a portion of the polymer nanoparticles are non-coupled to a reinforcing filament or a polymer nanoparticle.

11. The composition of claim 8 , wherein:
at least a portion of the polymer nanoparticles are core-sheath nanoparticles additionally comprising a sheath encapsulating a core; and
the sheath being configured to melt-fuse to at least one reinforcing filament as a result of a temperature of the sheath reaching a glass transition temperature of the sheath.

12. The composition of claim 8 , wherein:
at least a portion of the polymer nanoparticles are formed of a thermoplastic material having a higher toughness than the resin.

13. The composition of claim 8 , wherein:
the polymer nanoparticles are formed of thermoplastic material comprising at least one of the following: acrylics, fluorocarbons, polyamides, polyolefins, polyesters, polycarbonates, polyurethanes, polyaryletherketones, polyetherimides, polyethersulfone, polysulfone, and polyphenylsulfone;
the resin is formed of thermosetting material comprising at least one of the following: polyurethanes, phenolics, polyimides, sulphonated polymer, a conductive polymer, benzoxazines, bismaleimides, cyanate esthers, polyesters, epoxies, and silsesquioxanes.

14. A method of manufacturing a composite structure, comprising:
directly and independently coupling a plurality of polymer nanoparticles to one or more reinforcing filaments of a fiber tow prior to one of pre-pregging or resin infusion of the fiber tow, the polymer nanoparticles being located in spaced relation to each other on one or more of the reinforcing elements, each reinforcing filament having a filament cross-sectional width;
the polymer nanoparticles having a particle cross-sectional width that is less than the filament cross-sectional width;
maintaining, using the polymer nanoparticles, a filament spacing between adjacent reinforcing filaments via the polymer nanoparticles prior to and during one of pre-pregging or resin infusion of the fiber tow; and
the polymer nanoparticles having a material composition configured to remain in a solid state below a cure temperature of a resin, and dissolve in the resin as a result of the temperature of the polymer nanoparticles reaching the cure temperature of the resin.

15. The method of claim 14 , wherein:
at least a portion of the polymer nanoparticles are coupled to at least one of the reinforcing filaments and/or to other polymer nanoparticles.

16. The method of claim 14 , wherein at least a portion of the polymer nanoparticles are core-sheath nanoparticles additionally comprising a sheath encapsulating a core, the step of coupling the polymer nanoparticles to one or more reinforcing filaments includes:
at least partially melt-fusing the sheath of the polymer nanoparticles to one or more reinforcing filaments as a result of a temperature of the sheath reaching a glass transition temperature of the sheath.

17. The method of claim 16 , wherein the step of melt-fusing the sheath of the polymer nanoparticles to the reinforcing filament includes:
heating the reinforcing filaments; and
spraying the polymer nanoparticles onto a heated reinforcing filament using a plume of gas containing polymer nanoparticles

Assignees

• Boeing Co

Inventors

• Wilenski Mark S
• Meure Samuel J
• Kozar Michael P

Classifications

• B82Y30/00 Primary

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C08J5/06 Primary

  using pretreated fibrous materials · CPC title

• B05D1/12

  Applying particulate materials (B05D1/06, B05D1/10 take precedence) · CPC title

• C08J2300/00

  Characterised by the use of unspecified polymers · CPC title

• B29C70/40

  Shaping or impregnating by compression (B29C70/34 takes precedence){not applied} · CPC title