Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Sep 16;15(18):3784.
doi: 10.3390/polym15183784.

Enhanced Interfacial Properties of Carbon Fiber/Maleic Anhydride-Grafted Polypropylene Composites via Two-Step Surface Treatment: Electrochemical Oxidation and Silane Treatment

Dong-Kyu Kim  1   2 , Woong Han  1   2 , Kwan-Woo Kim  1 , Byung-Joo Kim  3
Affiliations

Enhanced Interfacial Properties of Carbon Fiber/Maleic Anhydride-Grafted Polypropylene Composites via Two-Step Surface Treatment: Electrochemical Oxidation and Silane Treatment

Dong-Kyu Kim et al. Polymers (Basel). .

Abstract

The interfacial adhesion between carbon fibers (CFs) and a thermoplastic matrix is an important aspect that should be improved in manufacturing CF-reinforced thermoplastics with high strength and rigidity. In this study, the effects of a two-step surface treatment comprising electrochemical oxidation and silane treatment of the CF surface on the mechanical properties of CF/maleic anhydride-grafted polypropylene (MAPP) composites were confirmed. The surface characteristics of the treated CFs were analyzed via scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The tensile testing of a single CF and interfacial adhesion of the samples before and after the surface treatment were analyzed using a single-fiber testing machine and a universal testing machine. After the silane treatment, the roughness of the CF surface increased due to the formation of a siloxane network. In addition, the interfacial shear strength increased by ∼450% compared to that of the untreated CFs due to the covalent bond between the -NH2 end group of siloxane and MAPP. This two-step surface treatment, which can be performed continuously, is considered an effective method for improving the mechanical interface strength between the CF and polymer matrix.

Keywords: carbon fiber; composites; electrochemical oxidation; interfacial shear strength; silane treatment.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Schematic of the microbond test: (a) sample preparation and (b) debonding process.
Figure 2
Figure 2
Scanning electron microscopy images of the surface of the untreated, electrochemical-oxidation-treated, and electrochemical-oxidation/silane-treated carbon fiber; (a) AS-CF, (b) EO-CF, and (c) EOS3-CF.
Figure 3
Figure 3
Atomic force microscopy images of the surface of the untreated, electrochemical-oxidation-treated, and electrochemical-oxidation/silane-treated carbon fiber; (a) AS-CF, (b) EO-CF, and (c) EOS3-CF.
Figure 4
Figure 4
Fourier transform infrared spectra of the untreated, electrochemical-oxidation-treated, and electrochemical-oxidation/silane-treated carbon fibers.
Figure 5
Figure 5
Chemical reaction of silane on the oxidized carbon fiber surfaces.
Figure 6
Figure 6
X-ray photoelectron spectra of the carbon fiber samples; (a) wide-scan survey, (b) surface element concentration of the carbon fiber samples, (c) fitting curve of the Si2p peaks of EOS3-CF, (d) N1s spectra of the carbon fiber samples subjected to different treatments.
Figure 7
Figure 7
Interfacial shear strength and tensile test results of the untreated and surface-treated carbon fiber samples subjected to different conditions.
Figure 8
Figure 8
Schematic of the interfacial adhesion enhancement mechanism between the silane-treated carbon fiber and maleic anhydride-grafted polypropylene; (a) carbon fiber and maleic anhydride-grafted polypropylene covalent bonding mechanism, (b) mechanism of interpenetrating polymer network formation.
See this image and copyright information in PMC

References

    1. Kim K.-W., Kim D.-K., Kim B.S., An K.-H., Park S.-J., Rhee K.Y., Kim B.-J. Cure behaviors and mechanical properties of carbon fiber-reinforced nylon6/epoxy blended matrix composites. Compos. B Eng. 2023;112:15–21. doi: 10.1016/j.compositesb.2016.12.009. - DOI
    1. Perepelkin K.E. Oxidized (cyclized) polyacrylonitrile fibers: Oxypan. A review. Fibre Chem. 2003;35:409–416. doi: 10.1023/B:FICH.0000020769.42823.31. - DOI
    1. Park S.-J., Jang Y.S., Shim J.W., Ryu S.K. Studies on pore structures and surface functional groups of pitch-based activated carbon fibers. J. Colloid Interface Sci. 2003;260:259–264. doi: 10.1016/S0021-9797(02)00081-4. - DOI - PubMed
    1. Wu Q., Pan D. A new cellulose based carbon fiber from a lyocell precursor. Textil Res. J. 2002;72:405–410.
    1. Kumar P.S., Jayanarayanan K., Balachandran M. High-performance thermoplastic polyaryletherketone/carbon fiber composites: Comparison of plasma, carbon nanotubes/graphene nano-anchoring, surface oxidation techniques for enhanced interface adhesion and properties. Compos. B Eng. 2023;253:110560. doi: 10.1016/j.compositesb.2023.110560. - DOI

LinkOut - more resources