Isothermal crystallization kinetics of poly(vinylidene fluoride) in the α-phase in the scope of the Avrami equation

2009 ◽  
Vol 45 (5) ◽  
pp. 1328-1335 ◽  
Author(s):  
V. Sencadas ◽  
C. M. Costa ◽  
J. L. Gómez Ribelles ◽  
S. Lanceros-Mendez
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Vinylidene Fluoride ◽  
Avrami Equation ◽  
Isothermal Crystallization Kinetics ◽  
Α Phase ◽  
Poly Vinylidene Fluoride ◽  
Kinetics Of

Parameters characterizing the kinetics of the non-isothermal crystallization of polyamide 5,6 determined by differential scanning calorimetry

2014 ◽  
Vol 34 (4) ◽  
pp. 353-358 ◽  
Author(s):  
Yassir A. Eltahir ◽  
Haroon A.M. Saeed ◽  
Chen Yuejun ◽  
Yumin Xia ◽  
Wang Yimin
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Degree Of Crystallinity ◽  
Avrami Equation ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
Ozawa Model ◽  
Kinetic Crystallization ◽  
Kinetics Of

Abstract The non-isothermal crystallization behavior of polyamide 5,6 (PA56) was investigated by differential scanning calorimeter (DSC), and the non-isothermal crystallization kinetics were analyzed using the modified Avrami equation, the Ozawa model, and the method combining the Avrami and Ozawa equations. It was found that the Avrami method modified by Jeziorny could only describe the primary stage of non-isothermal crystallization kinetics of PA56, the Ozawa model failed to describe the non-isothermal crystallization of PA56, while the combined approach could successfully describe the non-isothermal crystallization process much more effectively. Kinetic parameters, such as the Avrami exponent, kinetic crystallization rate constant, relative degree of crystallinity, the crystallization enthalpy, and activation energy, were also determined for PA56.

Influence of the Crystallization Kinetics on the Microstructural Properties of γ-PVDF

2008 ◽  
Vol 587-588 ◽  
pp. 534-537 ◽  
Author(s):  
M.P. Silva ◽  
Vitor Sencadas ◽  
A.G. Rolo ◽  
Gabriela Botelho ◽  
Ana Vera Machado ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Optical Microscopy ◽  
Kinetic Parameters ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Vinylidene Fluoride ◽  
Microstructural Properties ◽  
Infrared Transmission ◽  
Poly Vinylidene Fluoride ◽  
Kinetics Of

The kinetics of the isothermal crystallization of the γ-phase Poly(vinylidene fluoride) has been investigated. Samples were prepared from the melt at different crystallisation temperatures and the variation of the microstructure of the samples was monitored with time by optical microscopy. Raman and Infrared transmission spectroscopies also show the appearance of the γ-phase for higher crystallisation temperatures. Two types of γ-phase spherulites have been identified. These spherulites represents different ways to obtain the γ-phase and show different thermal stability. The correlation between microstructure and kinetic parameters allows the tailoring of the microstructure by choosing the crystallisation conditions of the samples.

Isothermal and non-isothermal crystallization kinetics and predictive modeling in the solidification of poly(cyclohexylene dimethylene cyclohexanedicarboxylate) melt

2016 ◽  
Vol 49 (2) ◽  
pp. 132-156 ◽  
Author(s):  
Ying-Guo Zhou ◽  
Wen-Bin Wu ◽  
Gui-Yun Lu ◽  
Jun Zou
Keyword(s):  
Activation Energy ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Avrami Equation ◽  
Melt Crystallization ◽  
Crystallization Activation Energy ◽  
Cooling Rates ◽  
Isothermal Crystallization Kinetics ◽  
Wide Range ◽  
Kinetics Of

Isothermal and non-isothermal crystallization kinetics of polycyclohexylene dimethylene cyclohexanedicarboxylate (PCCE) were investigated via differential scanning calorimetry (DSC). Isothermal melt crystallization kinetics were analyzed using the traditional Avrami equation. Non-isothermal melt crystallization kinetics data obtained from DSC were analyzed using the extended Avrami relation and a combination of the Avrami equation and the Ozawa relationship. The glass transition temperature, equilibrium melting point, isothermal crystallization activation energy, and non-isothermal crystallization activation energy were determined. Furthermore, a predictive method based on the Nakamura model was proposed and was used to describe the non-isothermal crystallization kinetics based on the isothermal experimental data. The results suggested that the original Nakamura equation was not successful in describing the non-isothermal crystallization of PCCE over a wide range of cooling rates. It was found that the non-isothermal crystallization kinetics of PCCE, over a wide range of cooling rates, could best be described by modifying the differential Nakamura equation to include a varied Avrami index.

Study on the Isothermal Crystallization Kinetics of Polyvinyl Pyrrolidone/Polyamide 6 Blends

2012 ◽  
Vol 557-559 ◽  
pp. 1487-1491
Author(s):  
Shi Jie Zhang ◽  
Yi Wen Tang ◽  
Xin Li Yang ◽  
Li Hua Cheng
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Crystallization Rate ◽  
Polyamide 6 ◽  
Polyvinyl Pyrrolidone ◽  
Avrami Equation ◽  
Intermolecular Hydrogen Bonds ◽  
Isothermal Crystallization Kinetics ◽  
Kinetics Of

The Avrami equation was used in the study of the isothermal crystallization kinetics of Polyvinyl pyrrolidone/Polyamide 6 Blends. The addition of PVP can hinder the PA6 crystallization process, increase the crystallization half-time and make the crystallization rate decrease. The molecular entanglements and intermolecular hydrogen bonds between PA6 and PVP chains exert some influence also.

scholarly journals Isothermal Crystallization Kinetics of Poly(ethylene oxide)/Poly(ethylene glycol)-g-silica Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 648
Author(s):  
Xiangning Wen ◽  
Yunlan Su ◽  
Shaofan Li ◽  
Weilong Ju ◽  
Dujin Wang
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Rate ◽  
Poly Ethylene Glycol ◽  
Isothermal Crystallization Kinetics ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Kinetics Of

In this work, the crystallization kinetics of poly(ethylene oxide) (PEO) matrix included with poly(ethylene glycol) (PEG) grafted silica (PEG-g-SiO2) nanoparticles and bare SiO2 were systematically investigated by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM) method. PEG-g-SiO2 can significantly increase the crystallinity and crystallization temperature of PEO matrix under the non-isothermal crystallization process. Pronounced effects of PEG-g-SiO2 on the crystalline morphology and crystallization rate of PEO were further characterized by employing spherulitic morphological observation and isothermal crystallization kinetics analysis. In contrast to the bare SiO2, PEG-g-SiO2 can be well dispersed in PEO matrix at low P/N (P: Molecular weight of matrix chains, N: Molecular weight of grafted chains), which is a key factor to enhance the primary nucleation rate. In particular, we found that the addition of PEG-g-SiO2 slows the spherulitic growth fronts compared to the neat PEO. It is speculated that the interfacial structure of the grafted PEG plays a key role in the formation of nuclei sites, thus ultimately determines the crystallization behavior of PEO PNCs and enhances the overall crystallization rate of the PEO nanocomposites.

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