PSI - Issue 17

Anurag Singh et al. / Procedia Structural Integrity 17 (2019) 857–864 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Figure 6: Elastic tensile modulus of neat resin, nanocomposites produced with pristine (MWCNTs) and with functionalized (fMWCNTs) nanotubes at different concentrations

Figure 7: Tensile stress at break of neat resin, nanocomposites produced with pristine (MWCNTs) and with functionalized (fMWCNTs) nanotubes at different concentrations

4.6 Electrical surface resistance Figure 8 and Figure 9 depict the DC electrical surface resistance R of the manufactured nanocomposite having a bio based resin matrix and with different concentrations of respectively pristine and functionalized MWCNTs. Particularly, Figure 8 reports the values of resistance R for the nanocomposite at 0.5 and 1 of wt% content, as well as, for the neat resin sample, where a decrease of resistance is reported with an increase of the nanotubes concentration, when compared to the neat resin. Figure 9 reports the resistance R of the nanocomposites with the MWCNTs functionalized according to the previously described methodology and a wt% content of 0.1, 0.25, 0.5 and 1%. Here a different tendency was observed, i.e. an increase of the electrical surface resistance with an increase of the functionalized nanotubes content.

Figure 8: Surface resistance (in log 10 scale) of neat resin and nanocomposites produced with pristine MWCNTs at different concentrations

Figure 9: Surface resistance (in log 10 scale) of neat resin and nanocomposites produced with functionalized MWCNTs at different concentrations

5. Conclusions Chemical functionalization of MWCNTs was performed to increase the dispersion and interfacial bonding of the MWCNT’s reinforced epoxy composite. To proceed with t he chemical functionalization of the bulk of MWCNT’s, optimization of the process parameters was required. Different time of chemical functionalization were selected, and it was concluded that with the increase of time of functionalization, yield product obtained after filtration decreases as the time of heating was increased. However, percentage of functionalized product obtained after diluting in DMF remains same with the increase of time of heating. This leads to the selection of 30 minutes of heating time for functionalization of MWCNT’s and for fabricating the nanocomposite, as maximum yield of functionalized product was obtained for this heating time. Specimens wer e fabricated by using various concentrations of MWCNT’s . The prepared specimens were then subjected to mechanical and electrical characterization, to see the effect of carbon nanotubes on the mechanical and electrical properties of the pure epoxy specimens.