Electrical conductivity of PUR/MWCNT nanocomposites in the molten state, during crystallization and in the solid state

► Conductivity of molten and crystallized CNT/polyurethane nanocomposites is studied. ► Same electrical percolation threshold is obtained in the molten and solid state. ► Conductivity increases remarkably during crystallization from the melt. ► A small volume shrinkage during crystallization cannot justify conductivity increase. ► A transition to a more performing network takes place during crystallization process.