Improving the electrical conductivity of multi-phase polymer composites via plasticizer assisted nanoparticle dispersion

摘要

It is well-known that electrically conductive polymer composites can be fabricated via incorporating highlyconductive fillers such as carbon fibres (CFs) and carbon nanotubes (CNTs) into a polymer system through either meltblending or solvent casting method. Nevertheless, one of the greatest challenges lies in the proper particle dispersion toachieve a low percolation threshold and high conductivity performance. Recently, it was found that CNTs have phasesensitivelocalization property when incorporated in a composite system formed by two immersible phases, such aspolylactic acid (PLA) and thermoplastic polyurethane (TPU). As a result, composites with ultra-low percolationthreshold can be formed by tuning the ratio of the two polymer phases. In this study, we reported that such property canbe further enhanced via the introduction of a small amount of plasticizer into the polymer system. It was observed thatthe incorporation of poly(ethylene glycol) (PEG) affected the immiscibility of the two polymer matrix as significantchanges in morphologies and thermal behaviours were also detected. Finally, by adding 5 wt% PEG, the electricalconductivity for sample contacting 2.5 wt% CNT increased from to 6.8 ×10~(-6) to 3.6 ×1~(-4) S/cm. Such results suggest thatplasticizer is an effective agent for improving particle distribution and conductivity enhancement.