MWCNT/PPO/PS nanocomposite

Figure 5.8 SEM micrograph of the surfece of a MWCNT/PPO/PS nanocomposite containing 0.75 wt% of MWCNTs. Scale bar 1 pm.

Figure 5.9 shows the electrical conductivity of the MWCNT/ PPO/PS nanocomposites as a function of the weight fraction of the MWCNTs. The percolation threshold is already reached at about 0.3 wt% MWCNT. As for the other series of nanocomposites studied, the conductivity is in the range of several tens of S/m at higher MWCNT concentrations [i.e., higher than 1 wt%]. 

Figure 5.9 Results of four-point conductivity measurements as a function of the MWCNT concentration for MWCNT/PPO/PS nanocomposites.

Figure 5.10 Two-point measurements of the conductivity of MWCNT/PPO/ PS nanocomposites as a function of the MWCNT concentration for 2 and 5 min of mixing in the extruder. The symbol ( ), at 6.7 wt% MWCNTs, corresponds to the conductivity of the pure masterbatch (MWCNT /PS before extrusion).

Here, an alternative approach based on masterbatches is presented in order to prepare CNT/PPO/PS nanocomposites. Instead of directly mixing a surfactant-CNT dispersion with a PPO/ PS polymer in the form of a latex, the nanocomposite was prepared in two steps. The first step consisted of producing a MWCNT/ PS masterbatch with a relatively high, well-dispersed MWCNT... 

Alternative route to prepare PPO/PS/MWCNT nanocomposites the masterbatch approach... 

---