Isothermal and Non-Isothermal Crystallization Kinetics of Conductive Polyvinylidene Fluoride/Poly(Ethylene Terephthalate) Based Composites

Abstract

This work deals with isothermal and non-isothermal crystallization kinetics of electrically conductive polyvinylidene fluoride/poly(ethylene terephthalate) (PVDF/PET) based composites. It completes our previous work in which we related the crystallinity of these conductive PVDF/PET based composites to their through-plane resistivity [1]. Isothermal crystallization was described using the logarithmic form of the Avrami equation and it was observed that the crystallization rate of the PVDF phase inside the composite became slower compared to that of neat PVDF. In nonisothermal crystallization, the Avrami exponent of PVDF phase did not show any noticeable variation; however, that of PET phase, which contains the major part of the conductive carbon black (CB) and graphite (GR) additives, showed an evident decrease compared with neat PET. It was also observed that, at the same cooling rate, the crystallization rate of PVDF and PET phases inside the composite was slower than that of neat PVDF and PET.

Study of Nonisothermal Crystallization Kinetics of Unstretched and Uniaxially Stretched Electroactive PVDF Composite Films

“…The value of "n" depends on type of nucleation and growth rate, and it lies between 1 and 4. Equation ( 1) can be rearranged into double logarithmic form as [20] ;…”

“…The value of “ n ” depends on type of nucleation and growth rate, and it lies between 1 and 4. Equation () can be rearranged into double logarithmic form as [ 20 ] ; $$$$\begin{equation*} {\rm{ln}}\,\left[{-{\rm{ln}}\,\left({1 - {X_{\rm{t}}}}\right)}\right] = n\ln t + \ln {k_t} \end{equation*}$$$$…”

“…Analysis of the crystallization behavior and involved kinetics are considered as an important factor in order to optimize their final material properties. [1] PVDF as a semicrystalline polymer, exists in five different crystalline phases (𝛼, 𝛽, 𝛾, 𝛿, 𝜖) and its macroscopic properties can be altered on the basis of their crystallization. [2] Several studies have already been reported about the nucleation of electro active DOI: 10.1002/macp.202200326 phases in PVDF by means of adding different nanoparticles such as ferrite nanoparticles, metallic nanofillers, inorganic fillers, carbon based fillers, and many more.…”