Polyimide/silica nanocomposites with low values of dielectric permittivity

Fragiadakis, D.; Logakis, E.; Pissis, P.; Kramarenko, Viktor Yu.; Shantalii, Tetyana A.; Karpova, I.L.; Dragan, K.S.; Привалко, Е. Г.; Usenko, Andrey A.; Privalko, V. P.

doi:10.1088/1742-6596/10/1/034

Cited by 32 publications

(18 citation statements)

References 8 publications

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“…5b exhibits higher values for the lower PDMS loading NCs. The same is true for dielectric permittivity (ε 0 ) and AC conductivity (s AC ) (Supplementary material SM.5), which are, however, higher than additivity values [48]. These results can be rationalized in terms of increased orientational polarization in the interfacial layer, at the lower PDMS content (to be further discussed below), in agreement with results reported recently for similar systems [19].…”

Section: Interfacial Dynamics (A Int Relaxation)supporting

confidence: 90%

Interfacial phenomena in core–shell nanocomposites of PDMS adsorbed onto low specific surface area fumed silica nanooxides: Effects of surface modification

Klonos

Sulym

Kyriakos

et al. 2015

Polymer

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Section: Interfacial Dynamics (A Int Relaxation)supporting

confidence: 90%

Interfacial phenomena in core–shell nanocomposites of PDMS adsorbed onto low specific surface area fumed silica nanooxides: Effects of surface modification

Klonos

Sulym

Kyriakos

et al. 2015

Polymer

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“…The demand for weak e 0 (T) and e 0 (f) dependencies, in addition to low absolute values, indicates that special attention must be paid to the investigation of the effects of the rigid inclusions on the dielectric strength of the secondary relaxations, which may contribute to e 0 (T) and e 0 (f). 29 For the isochronal semi-log e 00 (T) plots in Figure 5 a low frequency of 10 Hz has been chosen in order to follow, in a single plot, all the relaxations present in the pure epoxy network and the hybrids: the local, secondary c and b relaxations in the glassy state, the segmental a relaxation and the global NM relaxation in the temperature region of the glass transition, and dc conductivity and conductivity effects at higher temperatures. We will not further analyse dc conductivity here, we would like just to add one comment.…”

Section: Drs Measurementsmentioning

confidence: 99%

Polymer dynamics in rubbery epoxy networks/polyhedral oligomeric silsesquioxanes nanocomposites

Kourkoutsaki

Logakis

Kroutilová

et al. 2009

J of Applied Polymer Sci

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Dielectric techniques, including thermally stimulated depolarization currents (TSDC, À150 to 30 C) and, mainly, broadband dielectric relaxation spectroscopy (DRS, 10 À2 -10 6 Hz, À150 to 150 C) were employed, next to differential scanning calorimetry (DSC), to investigate molecular dynamics in rubbery epoxy networks prepared from diglycidyl ether of Bisphenol A (DGEBA) and poly (oxypropylene)diamine (Jeffamine D2000, molecular mass 2000) and modified with polyhedral oligomeric silsesquioxanes (POSS) units covalently bound to the chains as dangling blocks. Four relaxations were detected and analyzed: in the order of increasing temperature at constant frequency, two local, secondary c and b relaxations in the glassy state, the segmental a relaxation associated with the glass transition and the normal mode relaxation, related with the presence of a dipole moment component along the Jeffamine chain contour. Measurements on pure Jeffamine D2000 helped to clarify the molecular origin of the relaxations observed. A significant reduction of the magnitude and a slight acceleration of the a and of the normal mode relaxations were observed in the modified networks. These results suggest that a fraction of polymer is immobilized, probably at interfaces with POSS, due to constraints imposed by the covalently bound rigid nanoparticles, whereas the rest exhibits a slightly faster dynamics due to increaseof free volume resulting from loosened molecular packing of the chains (plasticization by the bulky POSS units).The increase of free volume is rationalized by density measurements.

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“…Typically, three relaxation processes are observed with increasing temperature designated as c, b, and a, respectively, with a corresponding to the glass-rubber relaxation. There are some reports, which refer to the characterization and analysis of the electrical and dynamical properties of polyimide hybrid films [36][37][38][39][40][41][42][43][44]. The properties of these materials are dependent on the interphase between filler and the polymer matrix.…”

Section: Introductionmentioning

confidence: 99%

The effect of zeolite L content on dielectric behavior and thermal stability of polyimide thin films

Hamciuc¹,

Hamciuc²,

Okrasa

et al. 2012

J Mater Sci

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Zeolite L, with the ratio Si/Al = 4, was prepared by hydrothermal method and used to obtain composite films based on a polyimide matrix having pendant carboxylic groups. The effect of zeolite L content on dielectric behavior and thermal stability of polyimide thin films was studied. The films were prepared by casting a suspension resulting from direct mixing of a poly(amic acid) (PAA) solution and zeolite L particles onto glass plates, followed by thermal imidization under controlled temperature conditions. The PAA was synthesized by solution polycondensation of a mixture of two diamines, 3,5-diaminobenzoic acid and 2,2-bis[4-(4-aminophenoxy)phenyl]propane (molar ratio 1:3), with 4,4 0 -oxydiphthalic anhydride, using N-methyl-2-pyrrolidone as solvent. To improve the compatibility between organic and inorganic phases, the surface of zeolite particles was modified by treating with 3-aminopropyltriethoxysilane. The surface morphology of the composite films investigated by scanning electron microscopy showed good compatibility between filler and polymer matrix. The films were flexible, tough, and exhibited high-thermal stability, having the initial decomposition temperature above 450°C. Dynamic mechanical analysis and dielectric spectroscopy revealed sub-glass transitions, c and b, and an a relaxation corresponding to the segmental motions above the glass transition temperature. The values of the dielectric constant at 10 kHz and 200°C were in the range of 3.3-4.2.

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Polyimide/silica nanocomposites with low values of dielectric permittivity

Cited by 32 publications

References 8 publications

Interfacial phenomena in core–shell nanocomposites of PDMS adsorbed onto low specific surface area fumed silica nanooxides: Effects of surface modification

Interfacial phenomena in core–shell nanocomposites of PDMS adsorbed onto low specific surface area fumed silica nanooxides: Effects of surface modification

Polymer dynamics in rubbery epoxy networks/polyhedral oligomeric silsesquioxanes nanocomposites

The effect of zeolite L content on dielectric behavior and thermal stability of polyimide thin films

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