Abstract
The influence of twin-screw extrusion on dispersion behaviour of multiwall carbon nanotube (CNT) in polycarbonate (PC) and consequently, its electrical conductivity and mechanical properties was investigated in more details than hitherto. Processing was carried out in a real production environment, using a Leistritz co-rotating extruder. Parameters investigated were extrusion temperature, screw speed, throughput, molecular weight (Mw) and CNT
concentration. Steady-state rheology over shear rates of 100–5000 s-1 was performed to observe the change in viscosity behaviour. Results demonstrated the incorporation of CNT have no influence of the processability. The rheological
behaviour of the various PCs were completely altered, exhibited intense shear thinning and lower shear viscosity than the virgin PC at shear rate greater than 600 s-1. Volume conductivity was found to increase with Mw and vice versa for
surface conductivity. A Lilly-like effect was observed in moving towards the lower and higher Mw end which had profound significance in predicting the conductivity behaviour of the PC/CNT. The presence of CNT appeared to give a
stabilising effect during processing against degradation. Compounds extruded at 280 ˚C and 300 rpm was found to give the most balance performance, in terms of conductivity and mechanical property. Finally, percolation plots was
performed using combination of optimised extrusion conditions. The PC/CNT displayed remarkable electrical conductivity, measuring 2x103 Ohm.cm at ca. 1 wt% CNT loading
concentration. Steady-state rheology over shear rates of 100–5000 s-1 was performed to observe the change in viscosity behaviour. Results demonstrated the incorporation of CNT have no influence of the processability. The rheological
behaviour of the various PCs were completely altered, exhibited intense shear thinning and lower shear viscosity than the virgin PC at shear rate greater than 600 s-1. Volume conductivity was found to increase with Mw and vice versa for
surface conductivity. A Lilly-like effect was observed in moving towards the lower and higher Mw end which had profound significance in predicting the conductivity behaviour of the PC/CNT. The presence of CNT appeared to give a
stabilising effect during processing against degradation. Compounds extruded at 280 ˚C and 300 rpm was found to give the most balance performance, in terms of conductivity and mechanical property. Finally, percolation plots was
performed using combination of optimised extrusion conditions. The PC/CNT displayed remarkable electrical conductivity, measuring 2x103 Ohm.cm at ca. 1 wt% CNT loading
| Original language | English |
|---|---|
| Publication status | Published - Oct 2009 |
| Event | Proceedings of the Polymer Processing Society Europe/Africa Regional Meeting - PPS 2009 - Laranca, Cyprus Duration: 01 Oct 2009 → 01 Oct 2009 |
Conference
| Conference | Proceedings of the Polymer Processing Society Europe/Africa Regional Meeting - PPS 2009 |
|---|---|
| Country/Territory | Cyprus |
| City | Laranca |
| Period | 01/10/2009 → 01/10/2009 |
Keywords
- CNTs
- polycarbonate