Isothermal and non‐isothermal crystallization kinetics of polyethylene terephthalate: Mathematical modeling and experimental measurement

Verhoyen, Olivier; Dupret, François; Legras, Roger

doi:10.1002/pen.10330

Cited by 45 publications

(22 citation statements)

References 30 publications

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“…Figure 9 gives a schematic of the effect of cooling rate on the relative degree of crystallinity. According to Verhoyen et al [54], the relative crystallinity was attributed to the primary and secondary crystallizations, respectively. Following Lauritzen and Hoffman [55], we defined three regimes in the cooling rate.…”

Section: Resultsmentioning

confidence: 99%

Effect of long chain branching on nonisothermal crystallization behavior of polyethylenes synthesized with constrained geometry catalyst

Yang

Wang

et al. 2011

Polymer Engineering & Sci

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Nonisothermal crystallization behavior of linear and long chain branched (LCB) polyethylene (PE) samples having similar molecular weight but different long‐chain branching densities (LCBD) up to 0.44 C per 1000 carbons was investigated using differential scanning calorimetry (DSC) at various scanning rates. The LCB PE samples were prepared in our high‐temperature, high‐pressure continuous stirred‐tank reactor (CSTR) system using the constrained geometry catalyst. The existence of LCB was found to affect the PE crystallization behavior considerably. The enthalpy of crystallization and the ultimate degree of crystallinity decreased with the increase of LCBD. At the relatively low cooling rates, the small amount of LCB promoted nucleation but restrained chain movement and reduced the crystal growth rate. There was ∼ 17% of crystallinity generated from a secondary crystallization. The energy barrier became significant with the LCB structure, resulting in chain diffusion limitations and lower LCB PEs overall crystallization rates than their linear counterpart. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

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Section: Resultsmentioning

confidence: 99%

Effect of long chain branching on nonisothermal crystallization behavior of polyethylenes synthesized with constrained geometry catalyst

Yang

Wang

et al. 2011

Polymer Engineering & Sci

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“…10 and fitted with Equation (11) for crystallization from the melt and cold crystallization. Activation energy values E t1 and E t2 range between 2.5 and 4.8 kJ mol À1 are low and consistent with literature [21,30]. Contrary to later modeling, induction times measured at 200 C, 260 C and 270 C have been taken into account to fit the model because they depend only on the beginning of the crystallization.…”

Section: Induction Time Modelingmentioning

confidence: 86%

“…This delay has also been observed for other polymers with low crystallization kinetics and modeled as a crystallization induction time (t i ) [21,30]. It corresponds to the time to reach a steady state of nucleation i.e.…”

Section: Thermal Analysis Methodsmentioning

confidence: 99%

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Isothermal crystallization kinetic modeling of poly(etherketoneketone) (PEKK) copolymer

Choupin

Fayolle

Régnier

et al. 2017

Polymer

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a b s t r a c tIsothermal melt and cold crystallizations of a poly(etherketoneketone) (PEKK) copolymer prepared from diphenyl ether (DPE), terephthalic acid (T) and isophthalic acid (I) with a T/I ratio of 60/40 have been investigated by differential scanning calorimetry, wide-angle X-ray scattering and polarized optical microscopy. For the first time, the two-stage overall crystallization kinetics of PEKK taking into account effects of nucleation and crystal growth has been identified by using a modified Hillier type model. The primary crystallization stage is found to be an instantaneous two dimensional nucleation growth with an Avrami exponent of 2 whereas the secondary stage is found to be an instantaneous one dimensional nucleation growth with an Avrami exponent of 1. The evolution of the crystallization kinetic constants for two-stage crystallizations has been modeled according to the Hoffman and Lauritzen growth theory. Due to low crystallization kinetics, a crystallization induction time has been added to obtain a good fit with experimental data. Based on this modeling, Time-Temperature-Transformation (TTT) diagrams of the relative volume crystallinity have been established for the overall crystallization mechanism and also for the separated primary and secondary crystallization mechanisms providing an original crystallization mapping of the material.

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“…Adoption of the Avrami equation for polymer systems is based on several assumptions and simplifications. The most important of them are as follows [5][6][7] :…”

Section: Introductionmentioning

confidence: 99%

Crystallization behavior of poly(N‐methyldodecano‐12‐lactam). III. Kinetics of isothermal crystallization

Kratochvíl

Sikora

2004

J of Applied Polymer Sci

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Differential scanning calorimetry, combined with Avrami theory, was used to investigate the kinetics of three steps of the complex crystallization process of poly(Nmethyldodecano-12-lactam) (MPA): (1) primary melt crystallization at respective crystallization temperature (T c ), (2) additional crystallization at 30°C, and (3) recrystallization at 54°C. Kinetics of the three steps was discussed with respect to T c . The Avrami exponent n of primary melt crystallization decreased between 2.5 and 1.9 in the range of T c values of Ϫ10 to 20°C, which suggests heterogeneous nucleation, followed by two-dimensional growth, with a larger involvement of homogeneous thermal nucleation at greater supercoolings. The crystallization rate constant k decreased with increasing T c . The value of n ϭ 1.5 for additional crystallization implies a two-dimensional diffusion-controlled crystal growth with a suppressed nucleation phase. For T c values ranging from Ϫ10 to 0°C and 0 to 20°C, k showed weak and quite strong decreasing dependencies on T c , respectively. The recrystallization mechanism involved partial melting of primary crystallites and two-dimensional rearrangement of chains into a more perfect structure. The rate of this process was almost independent of T c . The values of activation energies were derived for the three steps of MPA crystallization using the Arrhenius equation.

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Isothermal and non‐isothermal crystallization kinetics of polyethylene terephthalate: Mathematical modeling and experimental measurement

Cited by 45 publications

References 30 publications

Effect of long chain branching on nonisothermal crystallization behavior of polyethylenes synthesized with constrained geometry catalyst

Effect of long chain branching on nonisothermal crystallization behavior of polyethylenes synthesized with constrained geometry catalyst

Isothermal crystallization kinetic modeling of poly(etherketoneketone) (PEKK) copolymer

Crystallization behavior of poly(N‐methyldodecano‐12‐lactam). III. Kinetics of isothermal crystallization

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