scholarly journals Synthesis and Nonisothermal Crystallization Kinetics of Poly(Butylene Terephthalate-co-Tetramethylene Ether Glycol) Copolyesters

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1897 ◽  
Author(s):  
Hsu-I Mao ◽  
Chin-Wen Chen ◽  
Syang-Peng Rwei
Keyword(s):  
Crystallization Rate ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Excellent Thermal Stability ◽  
Butylene Terephthalate ◽  
Melt Polymerization ◽  
Ft Ir ◽  
Nonisothermal Crystallization Kinetics ◽  
Kinetics Of

Poly(butylene terephthalate-co-tetramethylene ether glycol) (PBT-co-PTMEG) copolymers with PTMEG ranging from 0 to 40 wt% were synthesized through melt polymerization. The structure and composition were supported by Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (1H NMR). All samples had excellent thermal stability at a Td−5% around 370 °C. Crystallization temperature (Tc) and enthalpy of crystallization (ΔHc) were detected by differential scanning calorimetry (DSC), revealing a decrement from 182.3 to 135.1 °C and 47.0 to 22.1 J g−1, respectively, with the increase in PTMEG concentration from 0 to 40 wt%. Moreover, nonisothermal crystallization was carried out to explore the crystallization behavior of copolymers; the crystallization rate of PBT reduced gradually when PTMEG content increased. Hence, a decrement in the spherulite growth rate was detected in polarizing light microscope (PLM) observation, observing that the PTMEG could enhance the hindrance in the molecular chain to lower the crystallinity of PBT-co-PTMEG copolyester. Moreover, thermal properties and the crystallization rate of PBT-co-PTMEG copolymers can be amended via the regulation of PTMEG contents.

Nonisothermal crystallization kinetics of polybutene-1 containing nucleating agent with acid amides structure

2014 ◽  
Vol 34 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Yongxian Zhao ◽  
Junyi Chen ◽  
Lei Han ◽  
Le Zhao
Keyword(s):  
Crystallization Process ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Mass Ratio ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Nucleation Effect ◽  
Activation Energy Of Crystallization ◽  
Nonisothermal Crystallization Kinetics ◽  
Kinetics Of

Abstract The nonisothermal crystallization behaviors of virgin isotactic polybutene-1 (iPB-1) and iPBn (iPB-1 containing a nucleating agent that owns acid amides structure; iPB/Mult920=100/0.5, mass ratio) were studied by means of differential scanning calorimetry (DSC). Modified Avrami theories (Ozawa method) and Mo method were used to analyze the DSC date. The results show that both methods are suitable to describe the crystallization process of iPB-1 and iPBn. Addition of 0.5% (mass ratio) nucleating agent can give rise to the nucleation effect, which increases the crystallization temperature (Tc) and the rate of crystallization of iPB-1, decreases the activation energy of crystallization (ΔE), and increases the crystallization rate of iPB-1 under the actual conditions.

scholarly journals Isothermal and Non-Isothermal Crystallization Kinetics of PVDF and PVDF/PMMA Blends

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Jianbin SONG ◽  
Yuan CAI ◽  
Bin ZHANG ◽  
Lixin TANG ◽  
Rongrong SHI ◽  
...  
Keyword(s):  
Activation Energy ◽  
Crystallization Kinetics ◽  
Crystallization Rate ◽  
Crystallization Activation Energy ◽  
Nonisothermal Crystallization ◽  
Ozawa Equation ◽  
Nonisothermal Crystallization Kinetics ◽  
Kinetics Of ◽  
Pmma Blends ◽  
Pure Pvdf

Background: poly(vinylidene fluoride) PVDF and PVDF/PMMA blends have been investigated with a focus on the crystal structure, immiscibility and mechanical properties. However, few reports were found on the crystallization behaviors of PVDF and PVDF/PMMA blends, especially on crystallization kinetics. The article is to report the research on isothermal and nonisothermal crystallization kinetics for PVDF and PVDF/PMMA blends using differential scanning calorimetry (DSC). Results: Besides crystallization temperature and isothermal crystallization activation energy, the Avrami equation exponent of PVDF in blends decreased compared with pure PVDF. The nonisothermal crystallization kinetics of PVDF and PVDF/PMMA (70:30) blends were investigated by Ozawa equation, Jeziorny method and crystallization rate constant (CRC) in detail. The nonisothermal crystallization energy of pure PVDF and its blends were determined by the Kissinger and Vyazovkin’s method. Conclusion: The nucleation and growth mechanism of PVDF in blends changed compared with pure PVDF. The Ozawa equation is not applicable in nonisothermal crystallization kinetics of PVDF and PVDF/PMMA blends. The decreasing of crystallization ability of PVDF in blends were found and confirmed by CRC and the decline of crystallization rate constant in Jeziorny method. Such is opposite to the results of Kissinger’s and Vyazovkin’s method, chances are that these two methods were not used to calculate the nonisothermal crystallization activation energy where the nucleation process was influenced.

Nonisothermal Crystallization Kinetics of Poly(ethylene terephthalate) Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 1812-1822 ◽  
Author(s):  
Jayita Bandyopadhyay ◽  
Suprakas Sinha Ray ◽  
Mosto Bousmina
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Ethylene Terephthalate ◽  
Ozawa Method ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Poly Ethylene Terephthalate ◽  
Nonisothermal Crystallization Kinetics ◽  
Poly Ethylene ◽  
Kinetics Of

This article reports the nonisothermal crystallization kinetics of poly(ethylene terephthalate) (PET) nanocomposites. The non-isothermal crystallization behaviors of PET and the nanocomposite samples are studied by differential scanning calorimetry (DSC). Various models, namely the Avrami method, the Ozawa method, and the combined Avrami-Ozawa method, are applied to describe the kinetics of the non-isothermal crystallization. The combined Avrami and Ozawa models proposed by Liu and Mo also fit with the experimental data. Different kinetic parameters determined from these models prove that in nanocomposite samples intercalated silicate particles are efficient to start crystallization earlier by nucleation, however, the crystal growth decrease in nanocomposites due to the intercalation of polymer chains in the silicate galleries. Polarized optical microscopy (POM) observations also support the DSCresults. The activation energies for crystallization has been estimated on the basis of three models such as Augis–Bennett, Kissinger and Takhor methods follow the trend PET/2C20A<PET/1.3C20A<PET, indicating incorporation of organoclay enhance the crystallization by offering large surface area.

Nonisothermal Crystallization Kinetics of Poly(m-xylylene adipamide)

2014 ◽  
Vol 971-973 ◽  
pp. 103-106
Author(s):  
Xiao Hua Gu ◽  
Peng Zeng ◽  
Xi Wei Zhang ◽  
Xue Song
Keyword(s):  
Differential Scanning Calorimetry ◽  
Crystallization Kinetics ◽  
Three Dimensional ◽  
Avrami Exponent ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Thermal Nucleation ◽  
Nonisothermal Crystallization Kinetics ◽  
Kinetics Of ◽  
Dimensional Crystal

Abstract.In this paper, the nonisothermal crystallization kinetics was investigated by differential scanning calorimetry for the poly(m-xylylene adipamide) (MXD6) which were prepared by polymerization in reactor. The Avrami theory modified by Jeziorny and Z.S. Mo equation were used to describe the nonisothermal crystallization kinetics. The analysis based on the Avrami theory modified by Jeziorny shows that the Avrami exponent n of MXD6 ranges from 2.3 to 3.3, Moreover, both Avrami exponent (n) were around 3.0, which probably suggests a thermal nucleation and a three-dimensional crystal growth. The good linearity of the plots indicates the successful application of Z.S. Mo method in this case.

Thermomechanical behavior and nonisothermal crystallization kinetics of poly(ε-caprolactone) and poly(ε- caprolactone)/poly(N-vinylpyrrolidone) blends

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhimin Xing ◽  
Liusheng Zha ◽  
Guisheng Yang
Keyword(s):  
Crystallization Kinetics ◽  
Biomedical Applications ◽  
In Situ Polymerization ◽  
Mechanical Energy ◽  
Crystallization Rate ◽  
Thermomechanical Analysis ◽  
Mechanical Analysis ◽  
Nonisothermal Crystallization ◽  
Nonisothermal Crystallization Kinetics ◽  
Kinetics Of

AbstractPoly(ε-caprolactone) (PCL) and PCL/Poly(N-vinylpyrrolidone) (PVP) blends are shown to have the potential to be used in a range of biomedical applications and can be processed with successive in-situ polymerization procedures. In this paper, the thermomechanical analysis of PCL and PCL/PVP blends was performed using dynamic mechanical analysis (DMA). The storage and loss moduli as a function of temperature and frequency were recorded. The nonisothermal crystallization kinetics of PCL and PCL/PVP blends were analyzed using Ozawa model and Mo-Liu equation, a combination equation of Avrami and Ozawa formulas. The Ozawa analysis failed to describe the nonisothermal crystallization behavior of blends, whereas the Mo-Liu equation successfully described the nonisothermal crystallization kinetics of PCL and PCL/PVP blends. In addition, the value of crystallization rate coefficient under nonisothermal crystallization conditions was calculated. The PCL/PVP blends compared with the pure PCL and PVP had a restrain effect on the crystallization kinetics of PCL in the blends. Combining the results of DMA and DSC, PVP effectively decreased the crystallinity of PCL and enhanced its damping properties, which indicated that PCL/PVP blends could be more suitable than PCL in some biomedical applications, as it might help in the dissipation of the mechanical energy generated by the patient movements.

Nonisothermal Crystallization Kinetics of HDPE/UHMWPE/n-HA Composites

2011 ◽  
Vol 194-196 ◽  
pp. 2351-2354 ◽  
Author(s):  
Hui Ling Shen ◽  
Na Zhang
Keyword(s):  
Activation Energy ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Relative Crystallinity ◽  
Small Deviations ◽  
Linear Portion ◽  
Activation Energy Of Crystallization ◽  
Nonisothermal Crystallization Kinetics ◽  
Avrami Parameter ◽  
Kinetics Of

The influence of compatibilizer and dispersant on the nonisothermal crystallization behavior of HDPE/UHMWPE/HA is investigated here by differential scanning calorimetry (DSC). It has been analyzed by Jeziorny method. For different composites, the Jeziorny plots shows the linear portion. The small deviations from linearity only appear at higher relative crystallinity because of the secondary crystallization. The value of Avrami parameter n is between 2.7 and 3.5. At the same temperature, Zcand Sibecome bigger after adding compatibilier and dispersant while tmax is decreasing. The activation energy of crystallization also have been studied by Kissinger equation. The result shows that the addition of compatibilizer and dispersant can decrease the activation energy. In addition, the compatibilizer and dispersant also improve the mechanical properties of composites.

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