Kinetics of isothermal and non-isothermal crystallization of poly(vinylidene fluoride) by fast scanning calorimetry. (15th January 2016)

• Record Type: Journal Article
• Authors: Gradys, A.; Sajkiewicz, P.; Zhuravlev, E.; Schick, C.
• Is Part Of: Polymer. Volume 82(2015)
• Page Start: 40
• Page End: 48
• Publication Date: 2016-01-15
• Subjects: Poly(vinylidene fluoride) -- Ultra-fast calorimetry -- Crystallization kinetics; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2015.11.020
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Crystallization from melt of poly(vinylidene fluoride) was studied by thin film chip calorimetry at cooling rates from 500 to 100, 000 Ks −1 and isothermally down to 76 °C. At ca. 70 °C, for cooling rates higher than 2000 Ks −1, there appears a change in crystallization from high temperature α phase to low temperature β phase. The amorphous state is preserved at cooling rate 100, 000 Ks −1 . Analysis of the crystallization kinetics with Ziabicki model reveals maximum of the steady-state crystallization rate of β phase as 2200 s −1 at 22 °C, and the highest crystallization rate of α phase as 200 s −1 at 70 °C. Approximation of the temperature dependent steady-state crystallization rate with the Turnbull and Fisher nucleation model results in the equilibrium melting temperatures 227 and 173 °C for the α and β phase, respectively, and in the energy barrier for short-distance transport, E D, as 70–80 kJ mol −1 at high supercooling. Graphical abstract: Highlights: Melt crystallization at ultra-high cooling rates using thin-film chip calorimetry. Steady-state crystallization rate of the α and β phase obtained with Ziabicki model. Approximation of the rate with the Turnbull and Fisher nucleation theory. Equilibrium melting temperatures and the energy barrier for short-distance transport.