Online raman spectroscopy observations during melt mixing of multiwalled carbon nanotubes with polystyrene to form composites

Multi walled carbon nanotube (MWCNT)/polystyrene (PS) composites were melt mixed in a small scale melt mixer fitted with a Raman probe in the backflow channel.composites with 1 wt.% and 2 wt.% MWCNT loadings were processed at two different screw speeds of 80 and 150 rpm at a constant temperature and residence time. Analysis of the Raman spectra showed an increase in tube defect concentration with higher CNT content and processing speeds. A decrease in the intensity of PS signatures in the composite with increased MWCNT content, screw speeds and residence time is observed. Although small changes in full width at half maximum of the Raman peaks of the composites are observed, no change in the MWCNT peak positions was found both in the melt and on the extruded composite. This work was carried out to understand our earlier investigation of MWCNT filled PS composites [1] in detail. The results observed by us differ to those published by other groups.