Nonisothermal crystallization kinetics of nylon 66/LCP blends

Jape, Sandeep Padmakar; Deshpande, V. D.

doi:10.1016/j.tca.2017.06.007

Cited by 23 publications

(22 citation statements)

References 66 publications

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“…Ideally, n and m should be identical, and a in Equation should be 1. Indeed, experimentally estimated values of a are typically close to 1 . Although F ( T ) and a do not provide any direct insights into the crystallization process, Song et al indicate that the appearance of the log β versus log t plot may hint at the crystallization mechanism change.…”

Section: Adjusting the Avrami Model To Nonisothermal Conditionsmentioning

confidence: 99%

“…Indeed, experimentally estimated values of a are typically close to 1. [6,[9][10][11][12] Although F(T) and a do not provide any direct insights into the crystallization process, Song et al [11] indicate that the appearance of the log b versus log t plot may hint at the crystallization mechanism change. For instance (Figure 3), this plot can reveal a breakpoint as in the case of the crystallization of poly(vinylidene fluoride).…”

Section: A Dj U Sti N G T He a V Ra M I M Od El To Non I Soth E Rm mentioning

confidence: 99%

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Nonisothermal crystallization of polymers: Getting more out of kinetic analysis of differential scanning calorimetry data

Vyazovkin

2018

Polymer Crystallization

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Differential scanning calorimetry data on nonisothermal crystallization kinetics of polymers are routinely parameterized in terms of the Avrami model. The parameterization is most commonly accomplished by the techniques proposed by Ozawa, Jeziorny, and Mo that are discussed briefly. The Ozawa technique frequently gives rise to nonlinear plots that do not enable determining the Avrami exponent. The Jeziorny technique appears inadequate for correctly evaluating the Avrami exponent. The Mo technique yields parameters whose numerical values cannot be directly interpreted in terms of the Avrami model. The emerging technique based on combining the Hoffman‐Lauritzen model with an isoconversional method is considered as a more rewarding alternative. This technique produces physically meaningful parameters capable of providing insights into the kinetics and mechanisms of nonisothermal crystallization. It is cautioned that the Kissinger method as well as some popular integral isoconversional methods (eg, Kissinger‐Akahira‐Sunose and Ozawa‐Flynn‐Wall) should not be used for evaluating the activation energy of the melt crystallization.

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Section: Adjusting the Avrami Model To Nonisothermal Conditionsmentioning

confidence: 99%

Section: A Dj U Sti N G T He a V Ra M I M Od El To Non I Soth E Rm mentioning

confidence: 99%

Nonisothermal crystallization of polymers: Getting more out of kinetic analysis of differential scanning calorimetry data

Vyazovkin

2018

Polymer Crystallization

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“…The isoconversional method of Friedman can be used to analyze the nonisothermal crystallization process. The nonisothermal crystallization activation energy (Δ E ) can be calculated from the degree of crystallinity using the Friedman equation expressed as follows:

ln {(\frac{dX}{dt})}_{X, i} = italicConstant - \frac{{∆ E}_{X}}{{italicRT}_{X, i}},

where ( dX / dt ) X,i is the relative crystallization rate as a function of time t at a given relative crystallinity X at a cooling rate denoted by i , T X , i is the temperature corresponding to X at cooling rate i , R is the universal gas constant (8.314 J/mol/K) and Δ E X is the activation energy at a conversion X . Δ E X at a conversion X can be obtained from the slope of the linear plot of ln ( dX / dt ) X , i versus the inverse of T X,i at different cooling rates.…”

Section: Resultsmentioning

confidence: 99%

Effect of nucleating agent supported on zeolite via the impregnation on the crystallization ability of isotactic polypropylene and its mechanism

Tong

Meng

et al. 2019

Polymers for Advanced Techs

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Addition of an α‐nucleating agent is the simple and effective method to increase nucleation efficiency of isotactic polypropylene (iPP). However, severe agglomeration and poor dispersibility of sodium 2,2′‐methylene‐bis(4,6‐di‐tertbutylphenyl) phosphate (NA11) decrease the nucleation efficiency in the iPP, and much more nucleating agent is needed to maintain the nucleating property. As a result, it becomes the key how to decrease the size of NA11 and increase the nucleating property. In this paper, zeolite 4A (Z4A) was firstly supported by NA11 through solution impregnation, and NA11 was dispersed by Z4A depending on the dispersion of zeolite as carrier for the second component. Then, the dispersed NA11 system (NA11‐Z4A) exhibited a superior nucleation behavior during the crystallization of the iPP matrix when it was used with iPP together. The isothermal and nonisothermal crystallization kinetics indicated that the NA11‐Z4A/iPP system had the best crystallization effect. Polarized optical microscopy (POM) and scanning electron microscopy (SEM) analyses showed that the size of NA11 decreased obviously when it was adsorbed on the surface of Z4A, which leads a better dispersibility of the nucleating agent and thus an accelerated nucleation process in the iPP matrix. In the end, the mechanism for the excellent dispersibility of NA11‐Z4A, which was based on hydrogen bonding between NA11 and Z4A, was confirmed by Fourier‐transform infrared spectroscopy (FTIR). Based on the research work, the solution impregnation strategy can potentially be applied to other systems to inhibit the agglomeration and improve the dispersibility of additives in iPP.

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“…On the other hand, t 1/2 of PA56 shows the opposite tendency (Figure d). Therefore, the DSC analyses show that with PA56 acting as a nucleating agent, the minor phase accelerates the crystallization rate of the matrix …”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the DSC analyses show that with PA56 acting as a nucleating agent, the minor phase accelerates the crystallization rate of the matrix. [50] As the POM and DCS tests reveal altered crystallization processes of PET and PA56 in the blends compared with the neat polymers, one might expect differences in the crystal forms and chains packing on a molecular level. In order to explore possible crystal reformations in the blends as compared with the neat polymers, we performed XRD measurements on the samples.…”

Section: Crystallization Behaviormentioning

confidence: 99%

Morphology and Crystallization of Biobased Polyamide 56 Blended with Polyethylene Terephthalate

Yan

Gooneie

et al. 2018

Macro Materials & Eng

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This study attempts to promote biobased polyamide 56 (PA56) as a sustainable candidate to replace commercial PA6 and PA66 when blended with polyethylene terephthalate (PET). Scanning and transmission electron microscopy of the blends with different PA56 contents reveals an immiscible morphology with an increase in the size of the dispersed domains by increasing PA56 content. The steady‐state mixing torque of the kneader is decreased to half by adding 10 wt% of PA56 to PET. Further addition of PA56 gradually increases this torque but does not surpass the neat PET sample up to 30 wt% of PA56. As revealed by microscopic dissipative particle dynamics (DPD) simulations, this gradual increase is ascribed to the difficulty to disperse larger domains of PA56 in the thermodynamically undesired PET. The results confirm that PA56 has a lubricating effect in PET. Using polarized optical microscopy (POM), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD) techniques, it is shown that PA56 acts as a nucleating agent in PET. This leads to the formation of numerous small crystals in the blends as opposed to several large crystals in the neat samples. The results encourage the use of PA56 biomaterial in combination with PET in products such as bicomponent segmented pie fibers.

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Nonisothermal crystallization kinetics of nylon 66/LCP blends

Cited by 23 publications

References 66 publications

Nonisothermal crystallization of polymers: Getting more out of kinetic analysis of differential scanning calorimetry data

Nonisothermal crystallization of polymers: Getting more out of kinetic analysis of differential scanning calorimetry data

Effect of nucleating agent supported on zeolite via the impregnation on the crystallization ability of isotactic polypropylene and its mechanism

Morphology and Crystallization of Biobased Polyamide 56 Blended with Polyethylene Terephthalate

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