Enhanced interfacial and mechanical properties of glass fabric/epoxy composites via grafting silanized carbon nanotubes onto the fibers

Abstract

AbstractFor enhancing the interfacial adhesion of glass fabric (GF)/epoxy composites, silanized multi‐walled carbon nanotubes (MWCNTs) were used to treat GF surface, where carboxyl MWCNTs were functionalized by silane coupling agents based on the covalent or non‐covalent bonding, followed by the vacuum infusion process of laminated composites. A detailed study was employed to confirm the effects of silanized MWCNTs uniform dispersion and interfacial properties of resultant composites. Making full use of suitable silane coupling agents (γ‐aminopropyltriethoxysilane) treatment, the uniform MWCNTs dispersion and strong fiber/matrix interfacial adhesion could be achieved. Compared with the control sample, flexural and interlaminar shear strengths of resultant composites were enhanced by about 24% and 22%, respectively, indicating superior mechanical strength for composites; flexural modulus and storage modulus in the glassy state were improved by about 36% and 68%, respectively, suggesting higher stiffness for composites; the work of fracture (Wf) under interlaminar shear tests was raised by about 188%, revealing better interlaminar fracture toughness of composites. In addition, glass transition temperature of resultant composites also increased. This work provides a guiding strategy for manufacturing fiber‐reinforced composites requiring adjustable strength, stiffness, and toughness.Highlights Silane coupling agent was grafted on MWCNTs by covalent/non‐covalent bonding. Active groups of silanized MWCNTs induced crosslinking reactions with matrix. Silanized MWCNTs dispersion and glass fiber/matrix adhesion were improved. Strengthening/toughening mechanisms of laminated composites were analyzed.