Crystallization and thermal conductivity of poly (vinylidene fluoride)/boron nitride nanosheets composites

In this work, boron nitride (BN) and exfoliated boron nitride nanosheets (BNNs) were employed as thermal conductive fillers to improve the thermal conductivity of poly(vinylidene fluoride) (PVDF) composites. Results suggested that the thermal conductivity of PVDF increases significantly with an increase in loading content of functional fillers. When the mass ratio of fillers was more than 30 wt%, the heat conduction network was formed. BNNs were capable of forming denser heat conduction network as per the SEM observations. In this scenario, PVDF/BNNs composites demonstrated excellent thermal conductivity. For example, the thermal conductivity of PVDF/BNNs (60/40) was 0.82 W/mK, which was 2.4 times and 17% higher than that of neat PVDF and PVDF/BN (60/40) counterpart, respectively. The non-isothermal crystallization of corresponding composite was studied by Mo method. Combining with XRD results, both BN and BNNs acted as the nucleation agents but had no effect on crystal forms.