Effect of temperature on the rheological properties of PVDF solutions made from green solvents

Poly (vinylidene fluoride), PVDF, is a commercially available semi-crystalline polymorphic polymer which is used in a wide variety of applications ranging from piezoelectric sensors and transducers to filtration membranes. PVDF processing controls the crystal morphology and polymorphism, including existence of the electroactive phases. Conventional synthetic solvents used in PVDF processing such as N,N-dimethyl acetamide (DMAc), N,N-dimethyl formamide (DMF), and N-Methyl-2-pyrrolidone (NMP) are extremely hazardous. Therefore, the need for environmentally friendly, non-toxic solvents in PVDF processing is a timely concern that requires immediate resolution: the processing conditions for PVDF solutions made from conventional solvents are not applicable to solutions made from green solvents. In this study, we report a comprehensive analysis on rheological properties of PVDF solutions made from two green solvents, γ-valerolactone (GVL) and dimethyl isosorbide (DMI) at three different compositions (5, 10, and 15 wt.%). Rheological properties are measured as a function of temperature and frequency. The crystal phases are evaluated using X-ray diffraction and infrared spectroscopy [1].

[1] Jayasekara, A. S., & Cebe, P. (2023). Quantitative analysis of polar crystalline fractions in poly (vinylidene fluoride) electrospun fibers and electrosprayed films. Polymer, 281, 126140.