Dual Nakamura model for primary and secondary crystallization applied to nonisothermal crystallization of poly(ether ether ketone)

Seo, Jiho; Zhang, Xiaoshi; Schaake, Richard P.; Rhoades, Alicyn M.; Colby, Ralph H.

doi:10.1002/pen.25767

Cited by 19 publications

(9 citation statements)

References 52 publications

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“…The Nakamura crystallization model is based on the Avrami–Erofeev nucleation model and Hoffman–Lauritzen crystal growth theory. A mathematical model called the Nakamura crystallization model is utilized to explain the crystallization kinetics of various materials [ 18 , 48 , 49 , 50 , 51 ]. The Avrami equation has been expanded by Nakamura et al [ 52 ] to describe the transformation process that takes place in non-isothermal crystallization based on isokinetic conditions.…”

Section: Resultsmentioning

confidence: 99%

“…The measured and predicted data match up best with the Nakamura crystallization model, which is based on the Avrami equation for nucleation and the Hoffman–Lauritzen crystallization theory. Additionally, Seo et al [ 48 ] used the dual Nakamura model for primary and secondary crystallization applied to non-isothermal crystallization of poly(ether ether ketone). Table 4 contains a list of the parameters that were obtained.…”

Section: Resultsmentioning

confidence: 99%

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Non-Isothermal Crystallization Kinetics of PBSu/Biochar Composites Studied by Isoconversional and Model Fitting Methods

et al. 2023

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Non-isothermal crystallization of Poly(butylene succinate) (PBSu)/biochar composites was studied at various constant cooling rates using differential scanning calorimetry. The analysis of the kinetics data revealed that the overall crystallization rate and activation energy of the PBSu polymer were significantly influenced by the addition of biochar. Specifically, the PBSu/5% biochar composite with a higher filler content was more effective as a nucleation agent in the polymer matrix, as indicated by the nucleation activity (ψ) value of 0.45. The activation energy of the PBSu/5% biochar composite was found to be higher than that of the other compositions, while the nucleation activity of the PBSu/biochar composites decreased as the biochar content increased. The Avrami equation, which is commonly used to describe the kinetics of crystallization, was found to be limited in accurately predicting the non-isothermal crystallization behavior of PBSu and PBSu/biochar composites. Although the Nakamura/Hoffman–Lauritzen model performed well overall, it may not have accurately predicted the crystallization rate at the end of the process due to the possibility of secondary crystallization. Finally, the combination of the Šesták–Berggren model with the Hoffman–Lauritzen theory was found to accurately predict the crystallization behavior of the PBSu/biochar composites, indicating a complex crystallization mechanism involving both nucleation and growth. The Kg parameter of neat PBSu was found to be 0.7099 K2, while the melting temperature and glass transition temperature of neat PBSu were found to be 114.91 °C and 35 °C, respectively, very close to the measured values. The Avrami nucleation dimension n was found to 2.65 for PBSu/5% biochar composite indicating that the crystallization process is complex in the composites.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Non-Isothermal Crystallization Kinetics of PBSu/Biochar Composites Studied by Isoconversional and Model Fitting Methods

et al. 2023

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“…Figure 5 b presents the L-H fitting to the crystal growth rate G of all the prepared materials, and the resulting parameters are presented in Table 2 . The U* values of all the samples are of the same order of magnitude as the universal value (6.3 kJ/mol [ 44 ]). The PEF/GNP nanocomposites present with a lower segmental activation energy, as expected.…”

Section: Resultsmentioning

confidence: 99%

Graphene Nanoplatelets’ Effect on the Crystallization, Glass Transition, and Nanomechanical Behavior of Poly(ethylene 2,5-furandicarboxylate) Nanocomposites

et al. 2022

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Poly(ethylene 2,5-furandicarboxylate) (PEF) nanocomposites reinforced with various content of graphene nanoplatelets (GNPs) were synthesized in situ in this work. PEF is a widely known biobased polyester with promising physical properties and is considered as the sustainable counterpart of PET. Despite its exceptional gas barrier and mechanical properties, PEF presents with a low crystallization rate. In this context, a small number of GNPs were incorporated into the material to facilitate the nucleation and overall crystallization of the matrix. Kinetic analysis of both the cold and melt crystallization processes of the prepared materials was achieved by means of differential scanning calorimetry (DSC). The prepared materials’ isothermal crystallization from the glass and melt states was studied using the Avrami and Hoffman–Lauritzen theories. The Dobreva method was applied for the non-isothermal DSC measurements to calculate the nucleation efficiency of the GNPs on the PEF matrix. Furthermore, Vyazovkin’s isoconversional method was employed to estimate the effective activation energy values of the amorphous materials’ glass transition. Finally, the nanomechanical properties of the amorphous and semicrystalline PEF materials were evaluated via nanoindentation measurements. It is shown that the GNPs facilitate the crystallization process through heterogeneous nucleation and, at the same time, improve the nanomechanical behavior of PEF, with the semicrystalline samples presenting with the larger enhancements.

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“…Crystallization dynamics affect polymer crystallization, crystal size, and crystal shape. The change in crystal structure is also capable of affecting the nucleation mechanism, surface free energy, and chain arrangement [ 1 , 2 , 3 , 4 , 5 ]. Understanding polymer crystallization, from both theoretical and practical points of view, is paramount for designing product macrostructures and regulating final properties.…”

Section: Introductionmentioning

confidence: 99%

Crystallinity, Rheology, and Mechanical Properties of Low-/High-Molecular-Weight PLA Blended Systems

Yang,

2023

Molecules

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As semi-crystalline polyester (lactic acid) (PLA) is combined with other reinforcing materials, challenges such as phase separation, environmental pollution, and manufacturing difficulties could hinder the benefits of PLA, including complete biodegradability and strong mechanical properties. In the present investigation, melt blending is utilized to establish a mixture of low- and high-molecular-weight polylactic acids (LPLA and HPLA). The crystallinity, rheology, and mechanical properties of the combination were analyzed using rotational rheometry, differential scanning calorimetry, X-ray diffraction, polarized optical microscopy, scanning electron microscopy, and universal testing equipment. The results demonstrate compatibility between LPLA and HPLA. Moreover, an increase in LPLA concentration leads to a decrease in the crystallization rate, spherulite size, fractional crystallinity, and XRD peak intensity during isothermal crystallization. LPLA acts as a diluent during isothermal crystallization, whereas HPLA functions as a nucleating agent in the non-isothermal crystallization process, promoting the growth of LPLA crystals and leading to co-crystallization. The blended system with a 5% LPLA mass fraction exhibits the highest tensile strength and enhances rheological characteristics. By effectively leveraging the relationship between various molecular weights of PLA’s mechanical, rheological, and crystallization behavior, this scrutiny improves the physical and mechanical characteristics of the material, opening up new opportunities.

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Dual Nakamura model for primary and secondary crystallization applied to nonisothermal crystallization of poly(ether ether ketone)

Cited by 19 publications

References 52 publications

Non-Isothermal Crystallization Kinetics of PBSu/Biochar Composites Studied by Isoconversional and Model Fitting Methods

Non-Isothermal Crystallization Kinetics of PBSu/Biochar Composites Studied by Isoconversional and Model Fitting Methods

Graphene Nanoplatelets’ Effect on the Crystallization, Glass Transition, and Nanomechanical Behavior of Poly(ethylene 2,5-furandicarboxylate) Nanocomposites

Crystallinity, Rheology, and Mechanical Properties of Low-/High-Molecular-Weight PLA Blended Systems

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