Experimental
Materials. A MWNT was supplied by the Hyperion Catalysis
International, Cambridge, MA. as a form of the PC/
MWNT masterbatch. Hyperion masterbatch consists of the
PC/MWNT (85/15 wt%). The MWNT was vapor grown and
typically consists of 8-15 graphitic layers.3,8 Typical diameter
of the MWNT is ranged from 10 to 15 nm, while length is
between 1 and 10μm.3,8 The Hyperion masterbatch was
diluted with the PC supplied by LG Chem. with the commercial
designation of PC 201 15. The characteristics of the
PC and Hyperion masterbatch are summarized in Table I.
Composite Preparations. PC/MWNT composites were
prepared by melt mixing using twin screw extruder. The
PC/MWNT composites, ranged from 0.5 to 15 wt% MWNT
content, were prepared by diluting the Hyperion masterbatch
with the PC. The temperatures of the extruder were set at
240 and 270 oC in feeding and barrel zone, respectively.
Samples were compression molded using hot press at 260 oC
for 5 min. Before sample preparation, all the samples were
dried under vacuum (