Non-Isothermal Crystallization Behavior of Poly(trimethylene Terephthalate-Co-Isophthalate) Copolyesters

2012 ◽  
Vol 535-537 ◽  
pp. 1413-1416
Author(s):  
Tien Wei Shyr ◽  
Chia Hsin Tung ◽  
Yan Ting Liu
Keyword(s):  
Isothermal Crystallization ◽  
Reaction Rate ◽  
Glassy State ◽  
Exothermic Peak ◽  
Avrami Equation ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
1H Nuclear Magnetic Resonance ◽  
Thermal Nucleation ◽  
Trimethylene Terephthalate

Poly(trimethylene terephthalate-co-isophthalate) (TI) copolyesters were synthesized using different ratios of isophthalic acid (IPA) and Terephthalic acid (TPA) with 1,3-propanediol (1,3-PDO). The compositions of TI copolyesters were analyzed using 1H nuclear magnetic resonance (NMR). Non-isothermal melt- and cold-crystallization and subsequent melting behaviors were investigated using differential scanning calorimetry (DSC). For TI0, TI10, and TI20, non-isothermal crystallization kinetics were analyzed using a modified Avrami equation. The results show that the reaction rate of TPA with 1,3-PDO was similar with that of IPA with 1,3-PDO in TI copolyesters. Crystallization exothermic peak and melting endothermic peak were not observed in DSC traces with an increase of the relative amount of PIP to 41%. The Avrami exponent n is in the range of 3.5-4.2 for melt-crystallized TI copolyesters and between 3.0-3.2 for cold-crystallized copolyesters. It suggests that the crystallization from melt state corresponds to thermal nucleation but the crystallization from glassy state originates from predeterminated nuclei.

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.

Non-isothermal crystallization kinetics of Poly(phenylene sulfide)/hyperbrtanched Poly(phenylene sulfide) blends

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Bo Yan ◽  
Yanmo Chen ◽  
Meifang Zhu ◽  
Ting Liu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Isothermal Crystallization ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
Cooling Crystallization ◽  
Hyperbranched Poly ◽  
Ozawa Equation ◽  
Thermal Nucleation ◽  
Kinetics Of ◽  
Phenylene Sulfide

AbstractThe non-isothermal crystallization behaviour of poly(phenylene sulfide) (PPS) in blends with hyperbranched poly(phenylene sulfide) (HPPS) was studied by means of differential scanning calorimetry (DSC). It was observed that the PPS crystallization temperature was found to decrease upon addition of the HPPS. It suggested that the crystallizability was reduced. The Ozawa equation was valid not only for neat PPS, but also for the blends. A notable reduction in Avrami exponents for the PPS/HPPS blend systems suggested that the nucleated process leads to rodshaped growth with thermal nucleation. The cooling crystallization function, which represents the rate of non-isothermal crystallization, was found to decrease with increase in HPPS content. The Ea value increases with the increase in HPPS content. Our results indicated that crystallization of the PPS was hampered by content of hyperbranched poly(phenylene sulfide).

Study of the crystallization kinetics of a Zr57Cu15.4Ni12.6Al10Nb5 amorphous alloy

2020 ◽  
Vol 111 (10) ◽  
pp. 849-856
Author(s):  
Hui E. Hu ◽  
Zhou Lu ◽  
Xiao Hong Su ◽  
Jing Xin Deng
Keyword(s):  
Amorphous Alloy ◽  
Crystallization Kinetics ◽  
Nucleation Rate ◽  
Isothermal Crystallization ◽  
Growth Process ◽  
Exothermic Peak ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
Diffusion Controlled

Abstract The non-isothermal crystallization kinetics with heating rates ranging from 10 K s-1to 80 K s-1and the isothermal crystallization kinetics during annealing from the glass transition temperature to the crystallization onset temperature of a Zr57Cu15.4Ni12.6Al10Nb5 amorphous alloy were studied in detail using X-ray diffraction and differential scanning calorimetry. During non-isothermal crystallization, it is more difficult to nucleate than to grow, and the crystallization resistance increases first and then decreases. During isothermal crystallization of the alloy from 713- 728 K, there are two exothermic peaks corresponding to a diffusion-controlled growth process with decreasing nucleation rate and increasing nucleation rate. From 733- 748 K, only one exothermic peak appears, and the growth process is controlled by the interface with decreasing nucleation rate. Isothermal crystallization is a process in which the crystallization resistance increases. The resistance of isothermal crystallization is less than that of non-isothermal crystallization.

Non-Isothermal Crystallization Kinetics and Melting Behaviors of Thermoplastic/Liquid Crystalline Polymer Blends of Poly(Trimethylene Terephthalate)/Vectra A950

2008 ◽  
Vol 54 ◽  
pp. 249-254 ◽  
Author(s):  
Penwisa Pisitsak ◽  
Rathanawan Magaraphan
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
Nucleation Effect ◽  
Trimethylene Terephthalate ◽  
Kinetics Of

The non-isothermal crystallization and subsequent melting behaviors of poly(trimethylene terephthalate), (PTT)/Vectra A950, (VA) blends with different VA contents were studied by differential scanning calorimetry. The effects of VA on the non-isothermal crystallization kinetics of PTT were discussed based on the Ozawa model. It was found that VA has a nucleation effect on PTT crystallization. The triple melting endotherms were found in the subsequent melting thermograms. The blends are clearly immiscible as verified by the unchanged Tg and morphological results.

scholarly journals Thermal Properties and Non-Isothermal Crystallization Kinetics of Poly (δ-Valerolactone) and Poly (δ-Valerolactone)/Titanium Dioxide Nanocomposites

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 452 ◽  
Author(s):  
Waseem Saeed ◽  
Abdel-Basit Al-Odayni ◽  
Abdulaziz Alghamdi ◽  
Ali Alrahlah ◽  
Taieb Aouak
Keyword(s):  
Titanium Dioxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Three Dimensional ◽  
Degree Of Crystallinity ◽  
Simultaneous Occurrence ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
The Stability ◽  
Kinetics Of

New poly (δ-valerolactone)/titanium dioxide (PDVL/TiO2) nanocomposites with different TiO2 nanoparticle loadings were prepared by the solvent-casting method and characterized by Fourier transform infra-red, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy, and thermogravimetry analyses. The results obtained reveal good dispersion of TiO2 nanoparticles in the polymer matrix and non-formation of new crystalline structures indicating the stability of the crystallinity of TiO2 in the composite. A significant increase in the degree of crystallinity was observed with increasing TiO2 content. The non-isothermal crystallization kinetics of the PDVL/TiO2 system indicate that the crystallization process involves the simultaneous occurrence of two- and three-dimensional spherulitic growths. The thermal degradation analysis of this nanocomposite reveals a significant improvement in the thermal stability with increasing TiO2 loading.

Non-isothermal crystallization behavior of polypropylene/zinc oxide composites

2016 ◽  
Vol 23 (5) ◽  
pp. 505-510 ◽  
Author(s):  
Jianqiang Fang ◽  
Minghua Lang ◽  
Xuchu Ye ◽  
Wei Zhang ◽  
Kongjun Zhu
Keyword(s):  
Activation Energy ◽  
Zinc Oxide ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Crystallization Kinetic ◽  
Exothermic Peak ◽  
Crystallization Time ◽  
Scanning Calorimetry ◽  
Relative Crystallinity ◽  
Oxide Composites

AbstractThe non-isothermal crystallization behavior of polypropylene (PP)/zinc oxide composites with various mass ratios was investigated by differential scanning calorimetry. The Jeziorny and Mo models were applied to calculate the non-isothermal crystallization kinetic parameters of the composites. During non-isothermal crystallization, the width of the exothermic peak increased from 7°C to 12°C with increasing cooling rate. The exothermic peak position at 10°C shifted to a lower temperature, and the half crystallization time t1/2 decreased from 2.86 min to 0.51 min. The Friedman model was used to determine the variation of activation energy at each stage of crystallization. The crystallization activation energies obtained varied significantly at each stage of crystallization. The crystallization activation energy of PP was -126.8 kJ/mol at 70% relative crystallinity but reached -232.8 kJ/mol at 10% relative crystallinity.

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