Interface enhancement of glass fiber fabric/epoxy composites by modifying fibers with functionalized MWCNTs

ABSTRACT

Functionalized multi-walled carbon nanotubes (MWCNTs) (with carboxyl, hydroxyl and amino groups, respectively) were grafted onto the surface of glass fiber fabric (GFf) for enhancing interfacial properties of corresponding epoxy-based composites. The effect of introducing various MWCNTs at the fiber/matrix interface was systematically investigated, including on the dispersibility of MWCNTs, interfacial microstructure, interlaminar and mechanical properties. The experimental results showed that the incorporation of functionalized MWCNTs could repair the interface defects, resist the interface debonding, and restrict the mobility of epoxy molecules around the fibers to enhance the interfacial adhesion. Furthermore, the interface layer of resultant composites was broadened with the incorporation of functionalized MWCNTs, and such transition region would transfer mechanical stress uniformly and delay material failure. By choosing the optimal MWCNTs with hydroxyl groups, the interlaminar shear, tensile and flexural strengths of MWCNTs-grafted GFf/epoxy composites were enhanced by 24.0%, 24.9% and 21.1%, respectively; the storage moduli in the glassy and rubbery regions were improved by 17.2% and 153.8%, respectively; the glass-transition temperature also increased by 7.6^°C.

Graphical Abstract

KEYWORDS:

• Polymer-matrix composites (PMCs)
• carbon nanotubes
• glass fibers
• interfacial microstructure
• mechanical properties

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Fundamental Research Funds for the Central Universities in China [grant number 2018B40814]; Postgraduate Research & Practice Innovation Program of Jiangsu Province [grant number KYLX16_0734].