Water Absorption Effect on the Dynamic Properties of Nylon-6 by Dielectric Spectroscopy

Laredo, E.; Grimau, M.; Sánchez, Francisco; Bello, A.

doi:10.1021/ma034954w

Cited by 81 publications

(134 citation statements)

References 28 publications

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“…For amorphous polymers, a non-symmetric distribution of times is expected for the α relaxation, associated with macromolecular segmental motion, at temperatures immediately above the glass transition. But for semi-crystalline polymers and more generally for heterogeneous systems, published data by Boyd [55], Laredo [56], Cebe [57], Noda [58], Ryabov [59], Janik [60], Feldman [61], Ortiz-Serna [29][30] etc., show that symmetrical distributions are observed for the α relaxation processes. However, the temperature dependence of a for the β process differs from that observed for the glass rubber relaxation since it decreases with temperature.…”

Section: Dielectric Measurementsmentioning

confidence: 99%

Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy

Redondo-Foj¹,

Carsí²,

Ortiz-Serna³

et al. 2013

J. Phys. D: Appl. Phys.

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A poly(vinylpyrrolidone-co-butyl acrylate) (60VP-40BA) membrane has been synthesized as a tractable and hydrophilic material, obtaining a water swelling percentage around 60%. An investigation of molecular mobility by means of Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA) and Broadband Dielectric Relaxation Spectroscopy (DRS) has been fulfilled in the dry membrane. Dielectric and viscoelastic relaxation measurements have been carried out on the 60VP-40BA sample at several frequencies between -150ºC to 150ºC .The dielectric spectrum shows several relaxation processes labelled as γ, β and α in increasing order of temperature, whereas in the mechanical spectrum only the β and α relaxation processes are completely defined. In the dielectric measurements, conductive contributions overlap the α-relaxation. The apparent activation energies have similar values for the β-relaxation in both, the mechanical and the dielectric measurements. The β process is related to the local motions of the pyrrolidone group and the γ process is connected with the butyl units motions, both located in the side chains of the polymer.

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Section: Dielectric Measurementsmentioning

confidence: 99%

Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy

Redondo-Foj¹,

Carsí²,

Ortiz-Serna³

et al. 2013

J. Phys. D: Appl. Phys.

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“…6 The presence of water and its influence in the dielectric response were previously studied in various polymeric systems. [7][8][9][10][11] Here, we concentrate on the change in the dielectric properties of highly filled composites in the presence of water, and report on the dielectric relaxation of moisture-absorbed and dry samples.…”

Section: Introductionmentioning

confidence: 99%

“…The method has been applied to various different material systems. [7][8][9][10][11][20][21][22] Electrical properties of materials can be determined from the impedance measurements by performing current measurements with applied voltage and using the geometrical capacitance C 0 , the geometry of the sample. For example, for the complex permittivity, " Ã is estimated from the current measurement as a complex capacitance C Ã for a given geometrical shape of the measurement electrodes, which determine the geometrical capacitance C 0 , Here, the angular frequency, !, independent material properties are of relative permittivity at high frequencies, " 1 , and Ohmic (direct-current) conductivity, 0 ; ı ¼ ffiffiffiffiffiffi ffi À1 p .…”

Section: Introductionmentioning

confidence: 99%

Change in dielectric relaxation with the presence of water in highly filled composites

Tuncer

2017

J. Adv. Dielect.

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It is important to determine the dielectric characteristics of semiconductor encapsulation materials based on epoxy resins. We employed the dielectric spectroscopy technique to investigate the dielectric relaxation in the presence of water and how it changes the relaxation. It was observed that the dielectric relaxation of the material was significantly influenced by absorbed water, the local segmental motion (also known as Johari-Goldstein ( ) relaxation) was influenced most by the presence of the water, it was modified by the wet sample compared to dry one, and required high activation energy. The relaxation related to the glass transition was contributed by the cooperative motion (the -relaxation) of the epoxy resin system. The -relaxation was shifted to a low temperature in the wet sample compared to dry one. The relaxation was modeled with a clear Vogel-Fulcher-Tammann-Hesse (VFTH) behavior; the Vogel temperature of the wet sample was 8 K lower than the dry sample. The presence of water acts as a plasticizer for the molecular relaxation, and speed-up the cooperative process. The measured data were also used to estimate the electrical properties of the resin system by employing an effective-medium model together with a porous media continuum model by taking into account the physical properties of the system. It is already known that the influence of water in semiconductor packaging is important in sensitive applications. The presented measurements and the analysis method would be appreciated within the semiconductor packaging community to improve material selection and performance evaluation efforts.

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“…Three relaxations can be identified in all samples. They were identified and reported for the pure PA6 [21][22][23][24]. In the present work, the effect of water on the relaxation processes is considered to be negligible, due to the initial drying of the materials prior to testing.…”

Section: Dielectric Spectroscopymentioning

confidence: 81%

“…This explains the increase in Young's modulus for the nanocomposites. Assignment of molecular motions associated with the β-relaxation is complicated and a number of varying opinions exist in the literature [21][22][23][24]. However, these motions should be connected with the motion of amide groups together with neighboring methylene groups, and size of this moving unit is comparable to the size of the fullerene C 60 molecule.…”

Section: Dielectric Spectroscopymentioning

confidence: 99%

Dielectric relaxation of fulleroid materials filled PA6 composites and the study of its mechanical performance

Sinitsin¹,

Zuev²

2015

Nanosist.: fiz. him. mat.

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The effect of fulleroid materials (fullerene C 60 and fullerene soot which is used for fullerenes production) on the mechanical properties of polymer nanocomposites based on polyamide 6 (PA6) was investigated. Composites were synthesized by direct mixing in an extruder. Dielectric spectroscopy was used to investigate the influence of nanoparticles on relaxation processes in the polymer matrix. It is found that the segmental relaxation processes becomes faster with the addition of fullerene C 60 . In contrast, the secondary processes of PA6/fullerene C 60 nanocomposites were observed to slow down with the addition of fullerene C 60 . This means that the local 'molecular stiffness' is increased, and a phenomenological link between the secondary relaxation times and the mechanical properties explains the increase in the Young's modulus of the nanocomposites upon the addition of C 60 . These observations suggest that nanoparticles can have a qualitatively different effect on the matrix polymer dynamics at different length scales, and caution must be taken in comparing the changes in the dynamics associated with different relaxation processes.

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Water Absorption Effect on the Dynamic Properties of Nylon-6 by Dielectric Spectroscopy

Cited by 81 publications

References 28 publications

Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy

Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy

Change in dielectric relaxation with the presence of water in highly filled composites

Dielectric relaxation of fulleroid materials filled PA6 composites and the study of its mechanical performance

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