The kinetics of CNT transfer between immiscible blend phases during melt mixing

The complete transfer of multiwalled carbon nanotubes (MWCNTs) from a poly(styrene acrylonitrile) (SAN) precompound into an initially unfilled polycarbonate (PC) phase during 5 min of discontinuous melt mixing in a microcompounder has been observed recently. However, the typical time scale of the occurring transfer is presently still unknown. Morphological investigations within our study revealed that similar results can be obtained when the SAN-MWCNT-precompound is melt blended with neat PC by continuous twin-screw extrusion. Additionally, the kinetics of the CNT transfer was also investigated in a kneading chamber. We found that the CNT transfer rate turned out to be strongly coupled to the development of the interfacial area of the blend. Furthermore, we evaluated the interplay and significance of the possible and presently only insufficiently understood transfer mechanisms. We proposed for the first time a correlation between major processing and blend parameters and the probability of carbon nanotube transfer due to the development of a nanoscaled wetting angle.