A facile approach to the scalable preparation of thermoplastic/carbon nanotube composites

Disentangling and dispersing multiwalled carbon nanotubes (MWCNTs) in thermoplastics by the existing melt compounding facilities where neither solvent nor liquid chemicals are allowed remains a great challenge. This challenge is addressed herein by combining ball milling with melt compounding. Specifically, ball milling is applied to disentangle MWCNTs and to eventually liberate each tube from agglomeration, and then the tubes are melt compounded with SSFs (PA6). A uniformly distributed MWCNT network is observed; obvious load transfer from the matrix to the tubes is evidenced by the presence of many firmly embedded tubes on the fracture surface. The electrical conductivity percolation threshold of PA6/MWCNT composites is found to be 2.5-3.0 wt%, in comparison with 5.0-8.0 wt% for PA6/stainless steel fiber composites. The PA6/MWCNT composite at 10.0 wt% shows a 76% increase in flexural modulus and 58% in flexural strength.