Crystallization, mechanical, and rheological behavior of polyvinylidene fluoride/carbon nanofiber composites

Composites of polyvinylidene fluoride (PVDF)/carbon nanofibers (CNFs) with different nanofiber contents were prepared by melt‐blending using a twin‐screw extruder by directly mixing CNFs with PVDF in the molten state. Fibers were extruded from the blended pellets. CNFs improved the nucleation efficiency of PVDF but the percent crystallinity decreased with increasing CNF concentration. X‐ray diffraction results showed a change in the α phase, but the transition to the β phase did not occur. Dynamic mechanical analysis (DMA) indicated an improvement in storage modulus and reduced damping factor with increasing CNF concentration. A complementary improvement in mechanical properties was determined from tensile test results. Rheological measurements indicated increased storage modulus, loss modulus, and viscosity values with an increased percentage of CNFs in the PVDF.