An effective method to improve the interfacial shear strength in GF/CF reinforced epoxy composites characterized by fiber pull-out test

We proposed an effective method for filling multiwall carbon nanotubes (MWCNTs) into the interfacial region of glass (GF), carbon fiber (CF)/epoxy. The MWCNTs were dispersed with dissolving sodium dodecyl sulfate in deionized water using ultrasonic dispersion, and then they were coated onto fiber surface. The functionalized GF/CF coated with MWCNTs was adopted to prepare the microbond specimens, and fiber content effect on interfacial shear strength (IFSS) was discussed. Results show that our method dose not impair the inherent fiber strength. The microbond test results show that the failure load of GF/epoxy has increased by 10%, 9.45% and 8.3% when fiber contents are 3-5, respectively. In terms of CF/epoxy, it increases by 61.5%, 8.88% and 20%. The IFSS improvement is due to the enhanced mechanical interlocking between MWCNTs, polymer chains and fiber surface. Our method presents high potential to give rise to high performance composites.