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

Choupin, Tanguy; Fayolle, Bruno; Régnier, Gilles; Paris, Christophe; Cinquin, Jacques; Brûlé, B

doi:10.1016/j.polymer.2017.01.033

Cited by 58 publications

(86 citation statements)

References 36 publications

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“…The crystallinity X c of PEKK 6002 is plotted in Figure as a function of the crystallization time at 230°C from the glassy state, calculated as:

X_{c} = \frac{{Δ H}_{m} - {Δ H}_{cc}}{{Δ H}_{100 %}}

where Δ H m is the melting enthalpy (J g −1 ), Δ H cc the cold crystallization enthalpy (J g −1 ), and Δ H 100% the fully crystallized polymer enthalpy, which was considered the same for PEEK equal to 130 J g −1. We compared these experimental results to Hillier's crystallization kinetics model expressed by:

X_{c} = X_{normalc \max} w_{1} ([], 1 - \exp ((), - K_{1} t^{n_{1}})) + w_{2} K_{2} n_{2} \int_{0}^{t} ([], 1 - \exp ((), - K_{1} θ^{n_{1}})) {(t - θ)}^{n_{2} - 1} \exp ([], - K_{2} {(t - θ)}^{n_{2}}) italicdθ

where X c max is the maximum crystallinity of PEKK 60/40 (Table ), n 1 and n 2 correspond to the Avrami exponents, K 1 and K 2 to the crystallization rate constants, and w 1 and w 2 to the weight factor for the primary and secondary crystallization, respectively. The Hillier model with parameters identified in a previous article for isothermal crystallization at 230°C is plotted in Figure .…”

Section: Resultssupporting

confidence: 90%

“…where ΔH m is the melting enthalpy (J g −1 ), ΔH cc the cold crystallization enthalpy (J g −1 ), and ΔH 100% the fully crystallized polymer enthalpy, which was considered the same for PEEK equal to 130 J g −1. [16] We compared these experimental results to Hillier's crystallization kinetics model [17] expressed by [1] :…”

Section: Crystallinity Measurement Of Pekk Platessupporting

confidence: 89%

“…Since PEKK is consolidated at a high temperature (around 360 C), chemical transformations of the macromolecular chains such as chain scission and crosslinking mechanisms can occur. [1,2] In addition, after consolidation, the matrix can crystallize with different crystalline ratios and morphologies depending on the cooling rate. [3][4][5][6] As reported for the other PAEKs, macromolecular modification at high temperatures [7,8] and crystallization [9][10][11][12][13][14][15] directly impact the mechanical properties of the PEKK matrix [6] and consequently, the composite.…”

Section: Introductionmentioning

confidence: 79%

“…Second, the results for crystallization at 230°C and 260°C are similar regarding the Young modulus. This could be due to the fact that for crystallization at 260°C, the polymer begins to crystallize during heating until the crystallization temperature, especially as the polymer passes through crystallization temperatures around 240°C; for this reason, we also investigate crystallization at 260°C from the melt. It can be observed that the Young modulus for crystallization at 260°C from the melt is close to crystallization at 200°C from the glassy state until 20%; it then stabilizes between 110 and 145 MPa.…”

Section: Resultsmentioning

confidence: 99%

“…The final mechanical performances of composite parts are strongly linked to the thermal cycle applied during their manufacturing. Since PEKK is consolidated at a high temperature (around 360°C), chemical transformations of the macromolecular chains such as chain scission and crosslinking mechanisms can occur . In addition, after consolidation, the matrix can crystallize with different crystalline ratios and morphologies depending on the cooling rate .…”

Section: Introductionmentioning

confidence: 98%

See 4 more Smart Citations

Influence of thermal history on the mechanical properties of poly(ether ketone ketone) copolymers

Choupin

Debertrand

Fayolle

et al. 2019

Polymer Crystallization

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Since poly(ether ketone ketone) (PEKK) is a good candidate as a matrix for composite structural parts, the mechanical properties of PEKK copolymers prepared from diphenyl ether, terephthalic acid (T), and isophthalic acid (I) with different T/I ratios were assessed at room temperature and above their glass transition temperature depending on the thermal history during processing. The influence of cooling conditions and macromolecular modifications at high exposure temperatures was investigated. Results show that modulus and yield properties for a given testing temperature follow a master curve driven mainly by crystallinity regardless of the PEKK copolymers. By modifying PEKK during exposures at 400°C, which leads to branching mechanisms before crystallization, it is shown that modified PEKKs follow the master curve, thus confirming the predominant role of crystallinity in small deformation properties. However, for some morphologies, depending on the crystallization conditions such as cold or melt crystallization, a slight deviation is observed from the global master curve.

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“…The crystallinity X c of PEKK 6002 is plotted in Figure as a function of the crystallization time at 230°C from the glassy state, calculated as:

X_{c} = \frac{{Δ H}_{m} - {Δ H}_{cc}}{{Δ H}_{100 %}}

X_{c} = X_{normalc \max} w_{1} ([], 1 - \exp ((), - K_{1} t^{n_{1}})) + w_{2} K_{2} n_{2} \int_{0}^{t} ([], 1 - \exp ((), - K_{1} θ^{n_{1}})) {(t - θ)}^{n_{2} - 1} \exp ([], - K_{2} {(t - θ)}^{n_{2}}) italicdθ

Section: Resultssupporting

confidence: 90%

Section: Crystallinity Measurement Of Pekk Platessupporting

confidence: 89%

Section: Introductionmentioning

confidence: 79%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

See 3 more Smart Citations

Influence of thermal history on the mechanical properties of poly(ether ketone ketone) copolymers

Choupin

Debertrand

Fayolle

et al. 2019

Polymer Crystallization

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Enhancing resistance of poly(ether ketone ketone) to high‐temperature steam through crosslinking and crystallization control

Veazey

Hsu²,

Gomez

2019

J of Applied Polymer Sci

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Poly(aryl ether ketone)s (PAEKs) are promising materials for harsh environments, such as in high‐temperature steam applications. Here, the effect of high‐temperature steam on the crystallinity and mechanical properties of existing poly(ether ether ketone) (PEEK) and PEKK(T/I) polymers is investigated. Differential scanning calorimetry (DSC), wide‐angle X‐ray scattering or diffraction (WAXD), and dynamic mechanical analysis experiments show these materials undergo significant crystallization and reorganization after prolonged exposure to steam and suffer from embrittlement. In addition, we show that xanthydrol‐based crosslinks can provide the dimensional stability and stabilize the PEKK crystal structure. Mechanical tests demonstrate that the ductility is preserved for longer exposures to steam compared to neat PEKK, whereas DSC and WAXD data indicate xanthydrol crosslinks effectively stabilize the crystal structure against steam‐assisted crystallization. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47727.

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Controlling Crystallization: A Key Factor during 3D Printing with the Advanced Semicrystalline Polymeric Materials PEEK, PEKK 6002, and PEKK 7002

Rodzeń

McIlhagger

Strachota

et al. 2023

Macro Materials & Eng

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Controlling the crystallization of advanced, high-performance polymeric materials during 3D printing is critical to ensure that the resulting structures have appropriate mechanical properties. In this work, two grades of polyetherketoneketone (PEKK 6002 and PEKK 7002) are used to print 3D specimens via a fused filament fabrication process. The samples are compared with polyetheretherketone printed under the same conditions. Two approaches for controlling the crystallization process are undertaken. The first involves adjustment of the chamber temperature between room temperature and 190 °C to create two regions where crystallization is governed by the slow diffusion process and elevated by limiting the nucleation process. The second approach involves selection of PEKK materials with varying crystallization kinetics, namely. Application of this method into 3D-printing process allows for printing semicrystalline materials with tailored mechanical, thermal, and chemical properties as either amorphous or in situ crystallized products. The studies undertaken here provide the basis to eliminate expensive and time-consuming post-processing of 3D fabricated parts. In particular, solutions for the avoidance of poor adhesion to the building plate and weak interlayer adhesion that can lead to warping are described. The materials are divided into three groups, slow, moderate, and too fast crystallization kinetics.

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

Cited by 58 publications

References 36 publications

Influence of thermal history on the mechanical properties of poly(ether ketone ketone) copolymers

Influence of thermal history on the mechanical properties of poly(ether ketone ketone) copolymers

Enhancing resistance of poly(ether ketone ketone) to high‐temperature steam through crosslinking and crystallization control

Controlling Crystallization: A Key Factor during 3D Printing with the Advanced Semicrystalline Polymeric Materials PEEK, PEKK 6002, and PEKK 7002

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