Electrical, morphological and rheological study of melt-mixed polystyrene/copper nanowire nanocomposites

Polystyrene and copper nanowires were melt-mixed at 200 degrees C and 50 rpm in 5 mL and 15 mL DSM co-rotating conical micro-compounders (DSM5 and DSM15), respectively. The electrical, morphological and rheological properties of the resulting nanocomposites were studied. The electrical percolation of nanocomposites is between 1.0 and 2.0 vol.-% for the composites prepared in DSM5 and above 2.0 vol.-% for the composites prepared in DSM15. SEM micrographs show smaller copper nanowire agglomerates inside polystyrene from DSM15 than those from DSM5. However, TEM micrographs reveal that both single copper nanowires and nanowire bundles coexist in the polymer matrix for the samples prepared in both micro-compounders. No obvious microstructure transition is detected by the dynamic rheological data at 200 degrees C.