Cyclodextrin as sizing for carbon fibers: new bonding mechanism improves adhesion in carbon fiber reinforced epoxy resin

Anna Becker-Staines; Wolfgang Bremser; Thomas Tröster

doi:10.1016/j.heliyon.2020.e03766

Cyclodextrin as sizing for carbon fibers: new bonding mechanism improves adhesion in carbon fiber reinforced epoxy resin

Heliyon. 2020 Apr 15;6(4):e03766. doi: 10.1016/j.heliyon.2020.e03766. eCollection 2020 Apr.

Authors

Anna Becker-Staines¹, Wolfgang Bremser¹, Thomas Tröster²

Affiliations

¹ University of Paderborn, Department of Chemistry, Coating Materials and Polymers, Warburger Str. 100, 33098 Paderborn, Germany.
² University of Paderborn, Department of Mechanical Engineering, Automotive Lightweight Construction (Leichtbau im Automobil), Warburger Str. 100, 33098 Paderborn, Germany.

Abstract

In this study, β-cyclodextrin was covalently bonded on carbon fibers and its influence through host-guest complex formation was analyzed. Since cyclodextrins act as host molecules for aromatic compounds, complex formations can be performed in carbon fiber reinforced epoxy resins, between the carbon fiber surface and the aromatic compounds of the surrounding plastic. This interface design leads to improved adhesion between fiber and plastic. An increase of the interfacial shear strength from 12 MPa to 38 MPa was detected. It was possible to increase the interfacial shear strength even further, to 41 MPa, through a prior complex formation with one of the plastics components. In addition to the micromechanical analysis, energy-dispersive x-ray spectroscopy and contact angle measurements were performed to confirm the covalent coating of cyclodextrin on the carbon fiber surface.

Keywords: Carbon fiber; Carbon fiber reinforced plastics; Cyclodextrin; Improved interfacial shear strength; Interface design; Materials chemistry; Materials science; Pull-out tests.