Improvement in Mechanical and Thermo-Mechanical Properties of Epoxy Composite Using Two Different Functionalized Multi-Walled Carbon Nanotubes

In this study, two types of functionalized multi-walled carbon nanotubes were dispersed in an epoxy resin system (SC-15) at room and elevated temperatures using a combination of sonication and high shear mixing methods to determine optimal mechanical and thermal properties. At first, 0.1 wt% - 0.3 wt% of amino-functionalized multi-walled carbon nanotubes (MWCNT-NH2) and carboxyl-functionalized multi-walled carbon nanotubes (MWCNT-COOH) were dispersed in part-A of SC-15 resin using a combination method. The mixture was then added to part-B of epoxy resin and cured using two different cycles (cycle A: at room temperature for 24 hours and post-cure at 93.33?C for 4 hours, cycle B: at 65.56?C for 5 hours). In addition, control samples (without MWCNTs) were also fabricated for baseline consideration under similar conditions. In all cases, epoxy with MWCNTs showed improved performance. Improvements in properties in MWCNT/epoxy samples prepared using cycle A were comparatively lower than samples prepared with cycle B. Flexural and thermo-mechanical results demonstrated maximum improvement in 0.2 wt% MWCNT-COOH modified epoxy samples prepared using cycle B. Improvements in performance for samples cured at elevated temperatures were attributed to better dispersion of MWCNTs due to reduced viscosity. On the other hand, increased number of functional groups present in MWCNT-COOH contributed to higher crosslinking resulting in the highest observed properties.