β -Phase Crystallization of Poly(vinylidene fluoride) in Poly(vinylidene fluoride)/Poly(ethyl methacrylate) Blends

The nature of the crystalline phase of poly(vinylidene fluoride) (PVDF) in compatible blends with poly(ethyl methacrylate) (PEMA) was investigated by using X-ray diffraction (XRD), infrared microscopy (IR) and differential scanning calorimetry (DSC). The β phase of PVDF was observed after quenching from the melt and further annealing above the glass transition temperature over a composition range. The PVDF/PEMA blend with weight ratio of 3:2 has formed higher content of PVDF β crystals than others. By taking advantage of fast cooling rate of ultrafast differential scanning calorimeter (UFDSC), the quenching process of blends was modeled and tested simultaneously, and the melting behavior of β crystals in all blends was investigated. Three types of crystallization behavior of β phase PVDF in blends were found after quenching-annealing at different temperatures.