High thermal conductivity of poly(vinylidene fluoride)/carbon nanotubes nanocomposites achieved by adding polyvinylpyrrolidone

In this work, carbon nanotubes (CNTs) were treated using polyvinylpyrrolidone (PVP). Different contents of pristine CNTs and PVP treated CNTs were introduced into poly(vinylidene fluoride) (PVDF) to prepare the PVDF/CNT and PVDF/CNT@PVP nanocomposites, respectively. The thermal conductivity measurement showed that there was the most appropriate PVP content, at which the nanocomposites exhibited the highest thermal conductivity. For all nanocomposites, the thermal conductivity increased gradually with increasing CNT (or CNT@PVP) content. However, more pronounced increase was observed for the PVDF/CNT@PVP nanocomposites. Research on the crystallization behaviors showed that PVP did not change the crystalline structure of PVDF matrix apparently. However, morphology characterization and rheological measurements showed that PVP greatly improved the dispersion of CNTs and induced denser CNT network structure in PVDF matrix through the special interaction between CNTs and PVP and the hydrogen bonding effect between PVDF and PVP. The denser CNT network structure and the intensified interfacial interaction between CNTs and PVDF were suggested the main mechanisms for the largely enhanced thermal conductivity of the PVDF/CNT@PVP nanocomposites.