Novel electrically conductive polyurethane/montmorillonite-polypyrrole nanocomposites

International audienceThis work describes the production of electrically conductive nanocomposites based on thermoplastic polyurethane (TPU) filled with montmorillonite-dodecylbenzenesulfonic acid-doped polypyrrole (Mt-PPy center dot DBSA) prepared by melt blending in an internal mixer. The electrical conductivity, morphology as well as the rheological properties of TPU/Mt-PPy center dot DBSA nanocomposites were evaluated and compared with those of TPU nanocomposites containing different conductive fillers, such as polypyrrole doped with hydrochloride acid (PPy center dot Cl) or dodecylbenzenesulfonic acid (PPy center dot DBSA) or montmorillonite-hydrochloride acid-doped polypyrrole (Mt-PPy center dot Cl), prepared with the same procedure. The TPU/Mt-PPy center dot DBSA nanocomposites display a very sharp insulator-conductor transition and the electrical percolation threshold was about 10 wt% of Mt-PPy center dot DBSA, which was significantly lower than those found for TPU/Mt-PPy center dot Cl, TPU/PPy center dot Cl and TPU/PPy center dot DBSA. Morphological analysis highlights that Mt-PPy center dot DBSA filler was better distributed and dispersed in the TPU matrix, forming a denser conductive network when compared to Mt-PPy center dot Cl, PPy center dot Cl and PPy center dot DBSA fillers. This morphology can be attributed to the higher site-specific interaction between TPU matrix and Mt-PPy center dot DBSA. The present study demonstrated the potential use of Mt-PPy center dot DBSA as new promising conductive nanofiller to produce highly conductive polymer nanocomposites with functional properties