Largely Improved Stretch Ductility and β-Form Room-temperature Durability of Poly(vinylidene fluoride) by Incorporating Aliphatic Polyketone

In this study, we attempt to prepare a new blending system of poly(vinylidene fluoride) (PVDF) and aliphatic polyketone (POK) by melt compounding. The latter is a promising engineering plastic with comprehensive mechanical performances. When POK acted as minor phase to homogeneously disperse in and intimately contact with PVDF matrix, the brittle tensile behavior of neat PVDF transferred into a remarkably flexible manner (the elongation at break increased for 20 times), and more interestingly, the roomtemperature durability of β-form PVDF in the uniaxially drawn blend film was obviously better than that in the neat PVDF film. Fourier transform infrared spectroscopy revealed that specific dipole interaction existed between CF_2 group of PVDF and C=O group of POK.The intermolecular dipolar interaction induced good compatibility in the PVDF/POK blends, as evidently proved by fine two-phase morphology and decreased melting points of POK crystals. Therefore, the good compatibility and interfacial enhancement are responsible for the improvement of the stretch ductility and β-form room-temperature durability of the PVDF/POK blends.