In the maslerbatch dilution protocol, masterbatches of PA6 and MWNT (without or with pre-treated Na-AHA and OTPB) were prepared (under the same extrusion conditions mentioned above except for the mixing time which was fixed at 10 min) prior to compounding with the other constituents.
Moreover, OTPB modified MWNT also exhibited a refined "network-like" structure of MWNT in 50/50 PA6/ABS blends as indicated by higher electrical conductivity at 2 wt% MWNT content of 1:1 MWNT:OTPB ratio as compared to the electrical conductivity of unmodified MWNT (of 2 wt%) based 50/50 PA6/ABS blends (12).
Multicomponent blends with MWNT pre-treated with OTPB exhibit orders of magnitude higher electrical conductivity as compared to blends with MWNT (without or pretreated with Na-AHA).
Mechanism of Improved Dispersion of MWNT in the Presence of No-AH A and OTPB
Na-AHA and OTPB) may get adsorbed on the surface of MWNT during the sonication process and may also penetrate into the bundles of MWNT.
Further, it has also been observed through FTIR spectroscopy that there is a feasibility of interaction between OTPB and PA6 chains.
Blends with masterbatch of OTPB modified MWNT also show refinement in the co-continuous structure.
Blends with masterbatch of OTPB modified MWNT show significant refinement in the phase dimension of PA6 phase as compared to the blends with p-MWNT, masterbatch of p-MWNT and masterbatch of Na-AHA modified MWNT.
Interestingly, blends with OTPB modified MWNT show a single crystallization exotherm at ~194[degrees]C i.e.
Further, blends with OTPB modified MWNT show a single crystallization exotherm for PA6 at ~194[degrees]C, again at a temperature lower than the crystallization temperature of PA6 in blends with MWNT or Na-AHA modified MWNT.
The second crystallization exotherm of PA6 is however, found to be absent for blends with OTPB modified MWNT (Fig.
ABBREVIATIONS ABS Acrylonitrile butadiene styrene AC Alternating current CNT Carbon nanotubes DC Direct current DLS Dynamic light scattering DSC Differential scanning calorimetry EA Ethylene-acrylate FTIR Fourier transform infrared MWNT MuHiwall carbon nanotube OTPB
Octadecyl triphenyl phosponium bromide PC Polycarbonate PP Polypropylene SAN Styrene acrylonitrile SWNT Single wall carbon nanotubes TEM Transmission electron microscopy THF Tetrahydrofuran REFERENCES