Simultaneous grafting of carbon nanotube and hyperbranched poly(thioether‐yne) onto carbon fiber via thiol‐alkyne click chemistry to improve interface properties of carbon fiber/epoxy composite

Abstract

AbstractAn efficient and fast technique was proposed to graft carbon nanotube (CNT) on carbon fiber (CF) using hyperbranched poly(thioether‐yne) (HPTEY) as bridging agent through thiol‐alkyne click chemistry reaction. The successful synthesis of CNT/HPTEY grafted CF (CF‐HPTEY‐CNT) was verified with Fourier transform infrared, x‐ray photoelectron spectroscopy, thermogravimetric analyzer, and scanning electron microscopy. The simultaneous introduction of CNTs and HPTEY could significantly improve the wettability and surface energy of CF, leading to that the interfacial shear strength (IFSS) of CF‐HPTEY‐CNT/epoxy composite evaluated using the microdroplet test was remarkably enhanced by 106.4% than pristine CF/epoxy composite. The bending strength for CF‐HPTEY‐CNT/epoxy composite was also significantly increased by 40.4% because of the effective stress transfer at interface. Furthermore, the monofilament tensile strength of CF‐HPTEY‐CNT showed an increase (by 3.3%) as compared with pristine CF, attributed to that the grafting CNTs and HPTEY remedied the CF surface defects. Therefore, this work is expected to offer a promising technique for developing advanced structural composite with outstanding interface and mechanical properties.Highlights An efficient and fast technique to modify CF via click chemistry was proposed. The grafting of HPTEY‐CNT increased the surface roughness and wettability of CF. IFSS of CF‐HPTEY‐CNT/epoxy composite was significantly increased by 106.4%. The CF‐HPTEY‐CNT/epoxy composite had superior mechanical properties.