Relaxation map of PETg‐montmorillonite composites: Nanofiller concentration influence on α and β relaxation processes

Couderc, H.; Saiter, Allisson; Grenet, J.; Saiter, Jean‐Marc; Boiteux, Gisèle; Nikaj, Erisela; Stevenson, Isabelle; D’Souza, Nandika Anne

doi:10.1002/pen.21249

Cited by 21 publications

(17 citation statements)

References 20 publications

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“…In such a conventional case, it is well established that the fragility index, noted m DSC thereafter and reported in Table 1, can be estimated from the slope of a linear fit to data. As expected, these values are in close agreement with fragility indexes reported in the literature [34,39,40]. The second concern is to consider only F-DSC data to estimate fragility indexes.…”

Section: Resultssupporting

confidence: 87%

Combining Flash DSC, DSC and broadband dielectric spectroscopy to determine fragility

Dhôtel

Rijal

Delbreilh

et al. 2015

J Therm Anal Calorim

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New experimental results focused on Flash DSC, DSC and broadband dielectric spectroscopy investigations are reported in this work. The fictive temperatures and fragility indexes are estimated from Flash DSC experiments and compared to values obtained from classical DSC. The consistency of the Tool-NarayanaswamyMoynihan model and fragility concept is then investigated over a large range of cooling rates. Indeed, the Flash DSC allows exploring thermal properties of materials over a continuous and broad range of heating and cooling rates, complementary to rates usually available with DSC. The reliability of investigations is also demonstrated by comparing results obtained from two model amorphous polymeric systems: polystyrene and poly(ethylene terephthalate)-glycol. The temperature dependence of the cooling rate obtained by Flash DSC and DSC is also compared to the temperature dependence of the relaxation times obtained from broadband dielectric spectroscopy, experiment considered as the reference concerning the fragility measurements. The comparison of these two dependencies implies a better understanding about the origin of the temperature dependence of the cooling rate.

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Section: Resultssupporting

confidence: 87%

Combining Flash DSC, DSC and broadband dielectric spectroscopy to determine fragility

Dhôtel

Rijal

Delbreilh

et al. 2015

J Therm Anal Calorim

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“…The first relaxation is detected at low frequency, which is most likely due to the enhanced trapping of charge carriers in the interface areas between nanofiller and the base polymer known as Maxwell–Wagner–Sillars (MWS) polarization. The driving force of this charge blockage is the conductivity difference between the two phases . Mobile charges migrate under the influence of the electric field and accumulate at the interface of the nanofiller and polymer matrix and form large electric dipoles that attempt to follow the orientation of the applied field.…”

Section: Resultsmentioning

confidence: 97%

Dielectric Relaxation Dynamics of Clay‐Containing Low‐Density polyethylene Blends and Nanocomposites

Eesaee

David

Demarquette

2020

Polymer Engineering & Sci

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Series of clay-containing nanocomposites have been prepared and investigated using frequency-domain dielectric spectroscopy at different temperatures. Different matrix materials have been used: neat low-density polyethylene (LDPE) with and without compatibilizer and co-continuous blends of LDPE with two grades of polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) copolymers. Two major relaxation modes were detected in the dielectric losses of all the nanocomposites and associated with Maxwell-Wagner-Sillars interfacial polarization and dipolar relaxation, respectively. Characteristic relaxation rates, activation energies, dielectric strength, and shape parameters of these relaxation mechanismes were calculated and discussed for the LDPE/clay nanocomposites. The addition of compatibilizer was found to slightly increase the dielectric loss of the nanocomposites while slowing the dynamics due to an improved dispersion. When combined with a high loading of nanofiller (15%), the compatibilizer addition led to lowfrequency dispersion. A new relaxation process was then observed for the nanocomposites with the blend matrix. Several speculations were made as to the origin of this phenomenon, all of which were related to the SEBS phase. POLYM. ENG. SCI., 60:968-978, 2020.

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“…On the other hand, amorphous PET (PETg), obtained by adding cyclohexane dimethanol in place of ethylene glycol11 is a clear amorphous polymer, which is extensively used in flexible packaging12 and in composite industry for the production of hybrid yarns (Comfil®). Compared to semicrystalline PET, the PETg offers a broader range of processing parameters,13 which, in composite industry, allows for cycle reduction.…”

Section: Introductionmentioning

confidence: 99%

“…Compared to semicrystalline PET, the PETg offers a broader range of processing parameters,13 which, in composite industry, allows for cycle reduction. PETg matrix nanocomposites were efficiently prepared by melt intercalation11, 12 and studied mainly concerning their relaxation behavior by calorimetric and dielectric characterization. On the other hand, no report of the rheological properties of the nanocomposite, which are very important in determining the processability of nanocomposite, can be found in literature.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the structure and mass transport properties of clay nanocomposites based on amorphous PET

Greco

Corcione

Strafella

et al. 2010

J of Applied Polymer Sci

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The aim of this work is to characterize the rheological and permeability behavior of nanocomposites based on amorphous poly(ethylene terephthalate) (PETg) and organically modified montmorillonites (omMMT), obtained by melt intercalation. The use of PETg instead of semicrystalline PET is believed to reduce the risks associated to organic modifier degradation during processing at high temperatures. X-ray and transmission electron microscopy analysis performed on the PETg nanocomposites showed that processing for long time at temperatures lower than melting of semicrystalline PET allowed to obtain a partially intercalated structure with some degree of exfoliation. The rheological behavior of PETg nanocomposites was studied as a function of shear rate in a coneplate rheometer in order to correlate the viscosity with the aggregation state of omMMT. A simple model accounting for an apparent increase of rheological units size, associated with the intercalation of PETg macromolecules into omMMT galleries, is proposed. The glass transition temperature, T g , as a function of the volume fraction of omMMT content of the nanocomposite, was measured using differential scanning calorimetry. Finally, the water vapour permeability of PETg nanocomposites was correlated to the volume fraction of the impermeable inorganic part of the omMMT.

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Relaxation map of PETg‐montmorillonite composites: Nanofiller concentration influence on α and β relaxation processes

Cited by 21 publications

References 20 publications

Combining Flash DSC, DSC and broadband dielectric spectroscopy to determine fragility

Combining Flash DSC, DSC and broadband dielectric spectroscopy to determine fragility

Dielectric Relaxation Dynamics of Clay‐Containing Low‐Density polyethylene Blends and Nanocomposites

Analysis of the structure and mass transport properties of clay nanocomposites based on amorphous PET

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