Investigation of microstructure and mechanical properties of polyvinylidene fluoride/carbon nanotube composites after electric field polarization: A molecular dynamics study

Molecular dynamics (MD) simulation was used to investigate the microstructure and mechanical properties of pure polyvinylidene fluoride (PVDF) and PVDF/carbon nanotube (CNT) composites with and without a polarization process. After annealing, the trans percentages of non-polarized PVDF and composites are improved by about 25% compared to the initial model of α-phase PVDF. For PVDF and composites with polarization process, the PVDF trans percentages can be further enhanced by around 10% compared to those without the polarization process. The mechanical properties of pure PVDF can be improved by blending the PVDF with CNTs and with the polarization process. The local shear strain analysis shows that the strength of PVDF around the CNTs have been enhanced, leading to higher brittleness of the composites at increasing CNT weight fractions. During the tensile process, the trans percentage of PVDF increases in the non-polarized cases with increasing strain, but are less sensitive to polarized cases.