Study on the effect of tailoring the segmented PU molecules on electrically conductive properties and percolation threshold of PU/MWCNTs nanocomposites

Herein, a series of electrically conductive polyurethane composites with multi-walled carbon nanotubes (PU/MWCNTs) were in-situ polymerized according to tailoring the segmented PU molecules. The ultralow percolation threshold of MWCNTs (0.057 wt%) in the composites was achieved and the electrically conductive properties were markedly enhanced. The conductivity in PU@MWCNTs1-0.5 % and PU@MWCNTs2-0.5 % was lower than 1.0 × 10 −1 ° S m -1 . While PU@MWCNTs3-0.5 % had the conductivity of over 1.0 × 10 -6  S m -1 , almost 4 orders of significance, which was attributed to the increasing of hard segments on the PU molecule. Furthermore, the high piezoresistive properties of the composites were also observed. Therefore, this work had the important sense in decreasing the low percolation thresholds of conductive polymer composites.