Electrically and thermally conductive thin elastic polymer foils containing SiC nanofibers

Abstract

Design and experiment of polymeric nanocomposites (NCs) for photovoltaic applications with outstanding electrical and thermal properties has been investigated with the introduction of SiC nanofibers (NFs) into the poly(trimethylene terephthalate)-blockpoly(tetramethylene oxide) (PTT-PTMO) copolymers. In order to enhance the electrical and thermal conductivity, different concentrations of SiC NFs, ranging from 0.1 to 3.0 wt %, have 2 been selected to mix with PTT-PTMO via in situ polymerization method. This reaction method is an excellent choice for incorporation of high amount of SiC NFs (3 wt %) into the polymer that was confirmed by morphological studies. From dielectric spectroscopy studies a percolating behavior was confirmed at low percolation threshold (less than 2% wt %). Furthermore, the 15 % increment for thermal conductivity appeared with combination of 0.5 wt % SiC NFs with PTT-PTMO copolymers, which can be affected by manufacturing process of NCs, state of nanofillers dispersion and aspect ratio of nanofillers.

Nanocomposites Based on Thermoplastic Polyester Elastomers

“…Moreover, as shown in Figure 4, for nanocomposites with SiC nanofibers, the values of electrical conductivity in low frequency range exhibit higher values than those of pristine matrix. This fact suggests that there are many connections between nanofibers, with small gaps of polymer between them, which promotes polarization phenomena [26]. Our further study on the electrical properties of PTT-PTMO/SiC nanocomposites with higher content of SiC confirmed the electrical percolation threshold (φ c ) equals to 1.7 [26].…”

“…Thus, the SEM Elastomers images of NCs surface suggest the "pulling out" SiC NFs from the polymer matrix during the brittle fracture of the sample [10]. Thus, it can be concluded that 1D type nanofillers, that is, SWCNTs, SiC NFs, with high aspect ratio distinctly represent their efficiency for avoiding the existence of agglomerates due to the high shear mixing with high-frequency vibration [10][11][12]26], thus confirming the legitimacy of the use of in situ method to obtain nanocomposites.…”

“…Moreover, the selected nanofillers, which were described in details in Refs. [10][11][12][13][14][15]26] have been listed as follows: SWCNTs with a diameter of <2 nm, length of 5-30 μm, purity higher than 95%, and surface area of 380 m 2 /g were bought from Grafen Chemical Industries, Grafen Co., Ankara, Turkey [10][11][12]; SiC nanofibers were produced via self-propagating high-temperature synthesis (SHS) from elemental Si and poly(tetrafluoroethylene) (PTFE) powder mixtures and provided by the group of Prof. A. Huczko [26]; GNPs in the form of a powder with less than three graphene layers, x-y dimensions of up to 10 μm, carbon content of ~97.0%, and the oxygen content of ~2.10% were bought from ANGSTRON Materials, Dayton, Ohio, USA [10][11][12]; GO sheets with average particle size of 50 μm obtained from expanded graphite (SLG Technologies GMbH, Germany) by Brodie oxidation method [27] were provided by the Polymer Institute of Slovak Academy of Science) [10,11]; octakis[(n-octyl)dimethylsiloxy]octasilsesquioxane (POSS) was obtained according to a sequential methodology presented in scheme in Ref. [12] and provided by the Centre for Advanced Technologies, Poznan, Poland).…”

“…Polymer nanocomposites based on carbon nanoparticles have enjoyed a big interest due to their enhanced mechanical and thermal properties along with electrical and thermal conductivity. In particular, nanocomposites based on carbon nanotubes (CNT), both SWCNTs and MWCNTs, carbon nanofibers, like SiC NFs [24,26,46], as well as graphene derivatives like GNP or expanded graphite (EG) have shown to exhibit exceptional mechanical strength and electrical conductivity [47][48][49][50][51][52][53][54][55]. In turn, in order to restore the electrical conductivity of : mass fraction of crystallinity.…”

Interfacial interactions in PTT–PTMO/polyhedral oligomeric silsesquioxane (POSS) nanocomposites and their impact on mechanical, thermal, and dielectric properties

“…This material exhibits excellent thermoplastic elastomer properties, such as a low glass transition temperature, high melting point, and a temperature-independent rubbery plateau [28]. However, more recently, it was found that the properties of PTT-PTMO can be further improved by the addition of either inorganic particles like montmorillonite (MMT) [29], POSS [23], silicon carbide nanofibers (SiC) [30] or organic nanofillers such as single-walled carbon nanotubes (SWCNT) [31], graphene oxide [32] or even a hybrid system of nanofillers like SWCNT and graphene nanoplatelets (GNP) [33,34]. However, it was found that at the same concentration, carbon nanofillers (like SWCNT or GNP) affect the polymer matrix in stronger manner [35].…”