Kinetics of non-isothermal crystallization process in various sized Li2B4O7 glasses

2004 ◽  
Vol 131 (2) ◽  
pp. 129-133 ◽  
Author(s):  
S.J. Kim ◽  
J.E. Kim ◽  
Y.H. Rim ◽  
Y.S. Yang
Keyword(s):  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Kinetics Of

scholarly journals Non-Isothermal Crystallization Kinetics of Poly(Ethylene Glycol)–Poly(l-Lactide) Diblock Copolymer and Poly(Ethylene Glycol) Homopolymer via Fast-Scan Chip-Calorimeter

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1156
Author(s):  
Dejia Chen ◽  
Lisha Lei ◽  
Meishuai Zou ◽  
Xiaodong Li
Keyword(s):  
Ethylene Glycol ◽  
Heterogeneous Nucleation ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Poly Ethylene Glycol ◽  
Ozawa Method ◽  
Isothermal Crystallization Kinetics ◽  
Fast Cooling ◽  
Poly Ethylene ◽  
Kinetics Of

The non-isothermal crystallization kinetics of double-crystallizable poly(ethylene glycol)–poly(l-lactide) diblock copolymer (PEG-PLLA) and poly(ethylene glycol) homopolymer (PEG) were studied using the fast cooling rate provided by a Fast-Scan Chip-Calorimeter (FSC). The experimental data were analyzed by the Ozawa method and the Kissinger equation. Additionally, the total crystallization rate was represented by crystallization half time t1/2. The Ozawa method is a perfect success because secondary crystallization is inhibited by using fast cooling rate. The first crystallized PLLA block provides nucleation sites for the crystallization of PEG block and thus promotes the crystallization of the PEG block, which can be regarded as heterogeneous nucleation to a certain extent, while the method of the PEG block and PLLA block crystallized together corresponds to a one-dimensional growth, which reflects that there is a certain separation between the crystallization regions of the PLLA block and PEG block. Although crystallization of the PLLA block provides heterogeneous nucleation conditions for PEG block to a certain extent, it does not shorten the time of the whole crystallization process because of the complexity of the whole crystallization process including nucleation and growth.

Study on Non-Isothermal Crystallization Kinetics of PBT with High Melt Flow Index

2012 ◽  
Vol 487 ◽  
pp. 58-63 ◽  
Author(s):  
Qing Yan Xu ◽  
Lin Wang ◽  
Yuan Liu ◽  
Zhi Hong Guo ◽  
Pei Jie Lin ◽  
...  
Keyword(s):  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Nonisothermal Crystallization ◽  
Isothermal Crystallization Kinetics ◽  
Avrami Index ◽  
Ozawa Equation ◽  
Kinetics Of

The non-isothermal crystallization process of PBT with high melt flow index has been investigated by DSC, and the nonisothermal crystallization process of PBT with high melt flow index was studied by Ozawa equation and Jeziorny equation respectively. It was found that Ozawa equation, rather than Jeziorny equation, could appropriately be applied to study the non-isothermal crystallization process of PBT with high melt flow index. The Avrami index, obtained by Ozawa equation, varied between 1.06-1.80 with the change in temperature.

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.

Cooling rate effects on the crystallization kinetics of polypropylene/date palm fiber composite materials

2016 ◽  
Vol 23 (5) ◽  
pp. 523-533 ◽  
Author(s):  
Sonia Boukettaya ◽  
Waseem Al Seddique ◽  
Ahmad Alawar ◽  
Hachmi Ben Daly ◽  
Adel Hammami
Keyword(s):  
Composite Materials ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Date Palm ◽  
Crystallization Process ◽  
Fiber Composite ◽  
Degree Of Crystallinity ◽  
Isothermal Crystallization Kinetics ◽  
Palm Fiber ◽  
Kinetics Of

AbstractNon-isothermal crystallization kinetics of polypropylene/date palm fiber (PP/DPF) composite materials were investigated in this study, using the differential scanning calorimetry (DSC) method. Different fiber contents and cooling rates, varying from 2.5°C/min to 20°C/min, were considered. The obtained results indicated that the initial crystallization temperature increases with the increase of the DPF content. This was attributed to the nucleating ability of these fibers. Several theoretical models were used to predict the non-isothermal crystallization kinetics of the materials considered in this study. Basically, it was shown that both the Avrami analysis, modified by Jeziorny, and the method developed by Mo could adequately describe such kinetics. The activation energies required during the overall crystallization process and at different amounts of the relative degree of crystallinity were also evaluated using the Kissinger method and the isoconversional analysis of calorimetric data, respectively. It was shown that the presence of the DPFs in the PP matrix decreases these energies, confirming their nucleating ability during the non-isothermal crystallization process.

Effect of Organoclay Platelets on Crystallization of PTT/EVA-g-MA Blends: Non-Isothermal Melt Crystallization Kinetics

2015 ◽  
Vol 1120-1121 ◽  
pp. 624-627
Author(s):  
Kun Yan Wang
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Process ◽  
Crystallization Rate ◽  
Melt Crystallization ◽  
Melt Mixing ◽  
Isothermal Crystallization Kinetics ◽  
Avrami Analysis ◽  
Kinetics Of

PTT/EVA-g-MA (80/20 w/w) nanocomposites were prepared by the melt mixing with different organoclay (OMMT) loading. The effect of OMMT on the non-isothermal crystallization kinetics of composites was investigated by DSC. The Avrami and Ozawa methods were used to describe the non-isothermal crystallization process of pure PTT and composites with various loading of OMMT. The Avrami analysis results show that the crystallization rate of 80/20 (w/w) PTT/EVA-g-MA blends with the OMMT is faster than that of pure PTT. The Ozawa analysis can describe the non-isothermal crystallization of pure PTT very well, but it was rather inapplicable for the 80/20 (w/w) PTT/EVA-g-MA blends with various amounts of the clay.

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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