Tactical tuning of mechanical and thermo-mechanical properties of glass fiber/epoxy multi-scale composites by incorporating N-(2-aminoethyl)-3-aminopropyl trimethoxysilane functionalized carbon nanotubes

摘要

The current study explores the potential of N-(2-aminoethyl)-3-aminopropyl trimethoxysilane (AEAPTS) functionalized single-wall carbon nanotubes (f-SWCNTs) as interface modifier to enhance thermomechanical characteristics of glass fiber/epoxy (GF/epoxy) composites. GF/epoxy laminates each embedded with 0.1, 0.3 and 0.5 wt% of pristine SWCNTs (p-SWCNTs) and f-SWCNTs, respectively, were fabricated using hot press technique. Fourier transform infrared spectroscopy demonstrated successful attachment of AEAPTS on SWCNTs while thermogravimetric analysis assessed the grafting density of AEAPTS. Tensile strength, modulus and interlaminar shear strength increased by similar to 27, similar to 14 and similar to 43%, respectively, at 0.5 wt% f-SWCNTs loading. However, no marked improvements were observed in mechanical properties with p-SWCNTs addition. Scanning electron microscopy revealed excellent dispersibility of f-SWCNTs in an epoxy matrix. Moreover, fractographic analysis revealed excellent compatibility of GF and epoxy resin in the presence of f-SWCNTs which accounts for improved interfacial adhesion. Dynamic mechanical thermal analysis showed similar to 40% increment in storage modulus at 25 degrees C with 0.5 wt% f-SWCNTs content whereas the glass transition temperature remarkably improved by similar to 13 degrees C as compared to the neat composite (similar to 136 degrees C). The cross-link density increased up to similar to 51% with f-SWCNTs addition implying that grafted AEAPTS moieties undergo a three-way cross-link reaction with epoxide groups of epoxy and silanes of glass fibers. Such multi-scale composites with enhanced strength and thermomechanical stability can replace metallic components in various engineering applications.