Enhanced β phase of polyvinylidene fluoride with addition of polyamide 6: role of interfacial interactions

Abstract

In this study, the polymer blends composed of polyvinylidene fluoride (PVDF) and polyamide 6 (PA6) were prepared via precipitation method, and then, the effects of PA6 on the crystallization behavior of PVDF, including the polymorphism and crystallization kinetice, were systematically investigated. For this aim, time-resolved Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimeter were utilized to study the influence of PA6 on crystallization behavior of PVDF. Furthermore, the morphologic images from scanning electron microscopy also supply the corresponding evidences. The results obtained shows that PA6 is immiscible with PVDF, while the PA6 component could form polar environment around the PVDF segment which is conducive to the formation of β phase of PVDF. In addition, calorimetric studies via DSC on the non-isothermal crystallization behavior and non-isothermal crystallization kinetics demonstrated conclusively that PA6 segments could effectively hinder the subsequent PVDF crystallization process because of the interfacial hydrogen bonds and incompatibility between PVDF and PA6.