Hybrid fiber tows containning both nano-fillers and continuous fibers, hybrid composites, and their production processes

Abstract

Disclosed is a hybrid fiber tow that comprises multiple continuous filaments and nanoscale fillers embedded in the interstitial spaces between continuous filaments. Nanoscale fillers may be selected from a nanoscale graphene plate, non-graphite platelet, carbon nano-tube, nano-rod, carbon nano-fiber, non-carbon nano-fiber, or a combination thereof. Also disclosed are a hybrid fiber tow impregnated with a matrix material and a composite structure fabricated from a hybrid fiber tow. The composite exhibits improved physical properties (e.g., thermal conductivity) in a direction transverse to the continuous fiber axis. A roll-to-roll process for producing a continuous fiber tow or matrix-impregnated fiber tow and an automated process for producing composite structures containing both continuous filaments and nanoscale fillers are also provided.

Description

[0001]This invention is based on the research results of a project supported by the U.S. Department of Energy (DOE) SBIR-STTR Program. The US Government has certain rights on this invention.FIELD OF INVENTION[0002]The present invention is related to a hybrid composite containing both a nano-filler and a continuous fiber dispersed in a matrix material. The nano-filler comprises nano-scaled graphene plates (NGPs), carbon nano-tubes (CNTs), carbon nano-fibers (CNFs), nano-clay platelets, nano-rods, or any other nanoscale reinforcement with at least an elongate axis. The matrix material comprises a polymer, organic, metal, ceramic, glass, carbon material, or a combination thereof. The nano-filler can be made to be substantially oriented in a preferred direction (e.g., with an elongate axis perpendicular to the continuous fiber).BACKGROUND[0003]Advanced composites, containing continuous fibers dispersed in a matrix material, are widely used in aerospace, sports equipment, infrastructure,...

AI Technical Summary

Benefits of technology

[0014]The versatility of the invented process opens up a window of many application opportunities for hybrid composites containing continuous fibers and nano-fillers such as NGPs, CNTs, and CNFs.

Problems solved by technology

In other words, these composites have excellent in-plane properties and relatively poor thickness-direction and shear properties.

Specifically, the thickness-direction and shear strengths and moduli of continuous carbon fiber reinforced polymer composite laminates are relatively poor.

Poor interlaminar shear strengths in turn lead to poor delamination resistance.

However, the addition of transverse reinforcements such as short (chopped) fibers is known to create processing difficulties.

The resulting matrix material, a nano-filler / resin mixture, is typically so viscous that it becomes extremely difficult to disperse continuous fibers in this matrix.

On the other hand, a low percentage (<5% by wt.) of nano-fillers normally does not provide adequate through-thickness thermal or electrical conductivity to a composite structure for certain engineering applications.

Fabrication of carbon nanotubes (CNTs) is expensive, particularly for the purifying process required to make them useful in applications.

Further, as indicated earlier, the loading of nano-fillers (e.g., CNTs and CNFs) increases the viscosity of the matrix resin to a level that is not conducive to subsequent filament winding and other automated composite manufacturing techniques.

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