Graphene-Peek Composites as Microwave-Activated High-Temperature Adhesives
ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY WATERVLIET United States
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Polyetheretherketone PEEK is a widely used engineering polymer that is especially suitable for high-temperature applications. Graphene is a two-dimensional form of carbon nanomaterial that has been studied extensively for its mechanical, electrical and thermal properties and its use as a filler in polymer matrices. Compounding graphene into polymers has the potential to improve various properties, even at very low concentrations. In this work, we have examined the incorporation of graphene nanoplatelets GNP into PEEK by fabricating composites using melt-mixing techniques, as well as by graphene functionalization and in-situ polymerization of the PEEK. In this way, we can compare the performance of the composites by two different processing methods. To examine mechanical properties and the viability of the composite as an adhesive, lap-shear joints using the GNP-PEEK as the adhesive were fabricated and mechanically tested. Results show that the weight fraction of GNP has a major effect on the strength of the joint. A 70 increase in lap-shear strength is demonstrated for the 2 wt GNP composite, as compared to the pure PEEK joints. In addition to the PEEK-GNP composites, lap shear samples were fabricated via 3D printing, with a layer of carbon nanofiber CNF-PLA printed as the adhesive. In this work, we aim to produce a material that functions as a reusable high-temperature, thermoplastic adhesive, which can be activated by conventional heating methods, or by microwave heating. Microwave heating allows only localized melting of the adhesive joint where the microwave absorbers are present GNPs or CNFs. The GNPs and CNFs absorb microwaves and heat the surrounding polymer matrix to the point of melting, in contrast to the neat polymer, which does not melt upon exposure to the microwaves under the same parameters. The dielectric and microwave absorption properties, as well as the adhesive properties of these advanced materials will be presented.
- Polymer Chemistry
- Physical Chemistry
- Adhesives, Seals and Binders
- Laminates and Composite Materials