Influence of Processing Parameters During Small-Scale Batch Melt Mixing on the Dispersion of MWCNTs in a Poly(propylene) Matrix



The relationship between varying processing variables, rotor speed (50 to 200 rpm) and mixing time (10 to 30 min), and MWCNT loading (0.5 to 2.0 wt%), on MWCNT dispersion in a poly(propylene) during batch melt mixing was investigated. MWCNT dispersion was improved by increasing rotor speed and/or mixing time, 200 rpm and 30 min being optimum, although composites prepared employing 100 rpm and 20 min were the most electrically conducting, (<100  S cm−1). PP shear viscosity increased with increasing MWCNT loading yielding a rheological percolation of ∼0.5 wt% MWCNTs. Volume resistivity of the composites decreased with increasing rotor speed and for mixing times up to 20 min only, the former yielding an electrical percolation of ∼0.65 wt% MWCNTs at 200 rpm.mame201300158-gra-0001