Electrical properties of polycarbonate/expanded graphite nanocomposites

In present study, polymer matrix nanocomposites based on polycarbonate as matrix and expanded graphite (EG) as reinforcement were fabricated using a simple solution method followed by hot pressing. Scanning electron microscopy revealed almost uniform dispersion and three dimensional networks of EG particles in the matrix. The dc and ac electrical conductivities of the nanocomposites increased with increasing EG content in the matrix. The electrical percolation threshold was observed between 1 and 2 wt % EG. The improvement in the conductivity of 10 wt % nanocomposite was found more than 13 orders of magnitude higher than that of pure matrix. The dielectric constant (at 1 MHz) of the nanocomposite containing 10 wt % EG was increased to about 137. The significant increase in electrical conductivity, dielectric constant, and dissipation factor for the nanocomposites might be good for the applications in antistatic/electromagnetic interference shielding applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47274.     

Thermal and electrical conductivity of melt mixed polycarbonate hybrid composites co‐filled with multi‐walled carbon nanotubes and graphene nanoplatelets

In this work, we present thermoplastic nanocomposites of polycarbonate (PC) matrix with hybrid nanofillers system formed by a melt‐mixing approach. Various concentrations of multi‐walled carbon nanotubes (MWCNT) and graphene nanoplatelets (GnP) were mixed in to PC and the melt was homogenized. The nanocomposites were compression molded and characterized by different techniques. Torque dependence on the nanofiller composition increased with the presence of carbon nanotubes. The synergy of carbon nanotubes and GnP showed exponential increase of thermal conductivity, which was compared to logarithmic increase for nanocomposite with no MWCNT. Decrease of Shore A hardness at elevated loads present for all investigated nanocomposites was correlated with the expected low homogeneity caused by a low shear during melt‐mixing. Mathematical model was used to calculate elastic modulus from Shore A tests results. Vicat softening temperature (VST) showed opposite pattern for hybrid nanocomposites and for PC‐MWCNT increasing in the latter case. Electrical conductivity boost was explained by the collective effect of high nanofiller loads and synergy of MWCNT and GnP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42536.     

Effect of exfoliated graphite nanoplatelets’ size on the phase structure,electrical, and barrier properties of poly(trimethylene terephthalate)‐based nanocomposites

This article describes the preparation process of two series of poly(trimethylene terephthalate) (PTT) nanocomposites with an addition of exfoliated graphite nanoplatelets with two different platelets’ size (50 and 500 μm). The influence of their size on processing, physicochemical properties, morphology and, most importantly, electrical conductivity and barrier properties of thin polymer films has been studied. It was clearly found that smaller platelets enabled to obtain conductive thin polymer films with a nanoplatelet content of 0.3‐0.5 wt.%. However, nanocomposite based on PTT with 0.5 wt% of EG with the flake size of 500 μm proved to be nonconductive. At the same time smaller EG platelets demonstrated a more uniform distribution in the PTT matrix, which was confirmed by means of scanning and transmission electron microscopies, thus giving the samples in question barrier properties with respect to CO₂ and O₂. Moreover, it has been shown that both nanofillers did not have a significant influence on the phase transition temperatures and on the long period. They caused however a slight decrease of crystallinity which is an evidence of an antinucleating character of those nanoplatelets in the PTT matrix. POLYM. ENG. SCI., 55:2222–2230, 2015. © 2015 Society of Plastics Engineers     

Synthesis and characteristics of poly(methyl methacrylate)/expanded graphite nanocomposites

In this work, we synthesized poly(methyl methacrylate) (PMMA)/expanded graphite (EG) nanocomposites by a new polymerization method. The volume electrical conductivity of the nanocomposite prepared by this way is very high (when the content of EG is about 8 wt %, the conductivity could reach 60 S/cm). The structure of the nanocomposite was investigated by SEM, TEM, IR, and XRD. And we found temperature and voltage were important parameters of governing the electrical conductivity of PMMA/EG nanocomposites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1427–1431, 2006     

Rheological,mechanical, optical,and transport properties of blown films of polyamide 6/residual monomer/montmorillonite nanocomposites

Exfoliated nanocomposites of polyamide 6 (PA6) with residual monomer and an organically treated montmorillonite (3 and 5 wt %) were produced by twin‐screw extrusion. The composites had their steady state, dynamic, and transient rheological properties measured by parallel‐plates rheometry; their exfoliation level was characterized by wide angle X‐rays diffraction (WAXD) and transmission electron microscopy (TEM). The characterization showed as follows: (i) the nanoclay's lamellas were well dispersed and distributed thru the PA6, (ii) the postpolymerization of the residual monomer produced more branched chains than linear ones in the pure PA6, (iii) the nanoclay's lamellas acted as entanglement points in the nanocomposites, and (iv) the molecular weight of the PA6 in the nanocomposites decreased. Blown films of the nanocomposites were produced by single screw extrusion; the die pressure during the film blowing of the nanocomposites strongly decreased. The tensile mechanical properties of the blown films were also measured. Along the machine direction (MD), the best mechanical properties were obtained with the 5 wt % nanocomposite, whereas along the transverse direction (TD), the 3 wt % nanocomposite had the best behavior. The glass transition temperature (T_g) of the blown films was measured by dynamic mechanical thermal analyses (DMTA). The 5 wt % nanocomposite had the highest T_g of all the films. The optical properties were measured by spectrophotometry; the nanoclay decreased the films' haze, but the level of transmittance was not affected. The water vapor and oxygen permeability rates of the nanocomposites films were found to be lower than in the pure PA6 blown film as a result of a tortuosity effect. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Electrical and mechanical properties of carbon nanotube‐epoxy nanocomposites

In this work, electrical conductivity and thermo‐mechanical properties have been measured for carbon nanotube reinforced epoxy matrix composites. These nanocomposites consisted of two types of nanofillers, single walled carbon nanotubes (SW‐CNT) and electrical grade carbon nanotubes (XD‐CNT). The influence of the type of nanotubes and their corresponding loading weight fraction on the microstructure and the resulting electrical and mechanical properties of the nanocomposites have been investigated. The electrical conductivity of the nanocomposites showed a significantly high, about seven orders of magnitude, improvement at very low loading weight fractions of nanotubes in both types of nanocomposites. The percolation threshold in nanocomposites with SW‐CNT fillers was found to be around 0.015 wt % and that with XD‐CNT fillers around 0.0225 wt %. Transmission optical microscopy of the nanocomposites revealed some differences in the microstructure of the two types of nanocomposites which can be related to the variation in the percolation thresholds of these nanocomposites. The mechanical properties (storage modulus and loss modulus) and the glass transition temperature have not been compromised with the addition of fillers compared with significant enhancement of electrical properties. The main significance of these results is that XD‐CNTs can be used as a cost effective nanofiller for electrical applications of epoxy based nanocomposites at a fraction of SW‐CNT cost. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of Cesium Aluminate Nanofiller on Optical Properties of Polyvinyl Pyrrolidone Nanocomposite Films

The nanocomposite films of poly vinylpyrrolidone (PVP) with different amounts viz., 2, 4, 6 and 8?wt% of cesium aluminate (CsAlO₂) have been fabricated using solvent casting technique. The effect of nanofiller content on the optical properties of PVP/CsAlO₂ nanocomposite films has been established by UV-visible spectroscopy. The UV-visible transmittance studies revealed that the UV light absorbing nature of nanocomposite films with considerable visible transparency. The Fourier Transform Infrared (FTIR) spectral studies visualizes the effect of CsAlO₂ nanofiller on the structural behaviors of PVP, while optical studies reveals an obvious change in the electronic band structure leading to a significant reduction in optical band gaps. The scanning electron microscopic (SEM) studies establish the morphological changes in PVP matrix upon doping with CsAlO₂. The measured refractive index (RI) depends on the volume fraction of CsAlO₂ nanofiller and the result indicates that a substantial increase of RI values from 1.85 to 2.64 at wave length 360 nm. The dielectric studies, optical conductivity measurements and Urbach energy analysis also supports the dopant dependent optical property, tuning of PVP/CsAlO₂ nanocomposite films to enable effective material property engineering to suit specified application requirements.     

Synergistic effects of conductive carbon nanofillers based on the ultrahigh-molecular-weight polyethylene with uniform and segregated structures

To discuss the synergistic effects of mixed conductive filler on nanocomposites, different structural carbon nanofiller/ultrahigh-molecular-weight polyethylene (UHMWPE) hybrid nanocomposites with uniform and segregated structure were prepared by using ethanol-assisted dispersion, hydrazine reduction, and hot-pressing methods. Scanning electron microscopy and polarized optical microscopy images of the nanocomposites fracture showed that the complete conductive channels could be formed in segregated nanocomposites prepared by powder mixing method. By contrast, the discontinuous electric path could be observed in the homogeneous nanocomposites prepared by the solution method. The test of conductivity performance demonstrated that the percolation threshold of carbon black (CB)/UHMWPE and multiwalled carbon nanotubes (MWCNTs)-CB/UHMWPE nanocomposites with segregated structure were 0.42 and 0.18 vol %, which were lower than those of the nanocomposites with uniform structure (4.91 and 2.62%). The electrical conductivity of MWCNTs-CB/UHMWPE nanocomposites with segregated structure reached to 3.0 × 10⁻² S m⁻¹ with the filler content of 1.5 vol %. In addition, the results of differential scanning calorimetry indicated that the crystallinity of UHMWPE decreased slightly with the addition of mixed filler. All of the study showed that the conductivity of MWCNTs-CB/UHMWPE nanocomposites with segregated structure has better electrical conductivity than the uniform. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47317.     

Convenient approach to making nanocomposites based on a chitosan–poly(vinyl pyrrolidone) polymer matrix and a graphene nanofiller

Conducting, mechanically durable, elastic nanocomposite films were prepared with chitosan (CS) as the polymer matrix, graphene obtained from highly exfoliated graphite as the nanofiller, and poly(vinyl pyrrolidone) (PVP) as the stabilizer of the graphene sheets. The maximum graphene content in the composites without a loss of uniformity and other useful properties increased up to 4.0 wt %. The resulting composites were characterized by scanning electron microscopy, Raman spectroscopy, X‐ray diffraction analysis, mechanical testing, and electrical conductivity testing to determine the effects of the addition of graphene on the morphology and mechanical and electrical properties of the CS–PVP–graphene nanocomposite films. In this study, we took an approach to making nanocomposites from the perspectives of green chemistry, environmental protection, regenerative medicine, and low cost. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45038.     

Preparation and characterization of new nanocomposite polymer films containing NiO nanofillers

Nanocomposite solid polymer films based on the poly(exo‐N‐phenyl‐7‐oxanorbornene‐5,6‐dicarboximide) (PPhONDI)/LiClO₄/NiO system have been designed, and the effect of inorganic NiO nanofiller in different amounts on the film properties has been examined. The exo‐PPhONDI/LiClO₄/NiO polymer system is the first solid nanocomposite polymer electrolyte film example based on a ring‐opening metathesis polymerization (ROMP) host polymer. The NiO nanoparticles were prepared by two‐step chemical syntheses, and the thermoplastic host polymer, exo‐PPhONDI, was synthesized via ROMP. Composite polymer films were prepared by the solution‐casting method. The amount of nanoparticles was varied from 1 to 15 wt % of NiO. The conductivity of the nanocomposite solid polymer systems was influenced by the NiO nanofiller concentration. The composite films based on exo‐PPhONDI ROMP polymer with the highest conductivity were achieved for the composition with 8 wt % of NiO nanofiller and 10 wt % of LiClO₄ dopant. The prepared films were characterized using X‐ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy (SEM). The SEM results showed that the filler was well distributed in the polymer matrix. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45938.     

Preparation and Characterization of High‐Performance Poly(trimethylene terephthalate) Nanocomposites Reinforced with Exfoliated Graphite

To improve the physical properties of poly(trimethylene terephthalate) (PTT), a series of nanocomposites based on PTT and exfoliated graphite (EG) are prepared via melt compounding and their structures, thermal stabilities, mechanical, and electrical properties are studied. XRD and SEM show that graphene nanosheets are well dispersed in the PTT matrix without forming crystalline aggregates even at high EG content. Thermal stability and dynamic mechanical moduli of the nanocomposites are substantially improved by EG addition, and a pronounced increase in electrical volume resistivity from an insulator to almost a semiconductor is observed with increasing EG content. The electrical percolation threshold of the nanocomposites is found to be formed at the EG concentration between 3.0 and 5.0 wt.‐%.

     

Synergistic effect of dual nanofillers (MWCNT and Ni–Al LDH) on the electrical and thermal characteristics of polystyrene nanocomposites

The advantage of using 3D hybrid filler containing carboxylic acid functionalized multiwalled carbon nanotubes (c‐MWCNTs) and sodium dodecyl sulfate modified Ni–Al layered double hydroxide (sN‐LDH) over c‐MWCNTs and sN‐LDHs acting alone was investigated. PS/c‐MWCNT composites proved to be good for improvement of properties, but not to an appreciable level, especially in case of electrical conductivity, flame retardancy, rheology, and water vapor permeability. Hence, a combination of 0.3 wt % of c‐MWCNT and 3 wt % of sN‐LDH was optimized as additives to assist in the full expression of the filler traits in the nanocomposite and to obtain a versatile nanocomposite with properties specific to both the fillers. This approach slightly decreases the dispersion challenge faced with handling high loadings of CNT and also the intrinsic limitations specific to the individual fillers (i.e., inertness of CNTs and low conductivity of LDHs). Moreover, the anion/anionic repulsion of organically modified CNT/LDH facilitates effective dispersion of the additive opposing adhesion. FTIR and Raman spectroscopy provided evidence for incorporation and proper dispersion of the additives in the polymer matrix, with XRD and TEM confirming a well‐dispersed morphology of the nanocomposites. In this work, focus is made on the improvement of thermal stability, flame retardancy, melt rheology, hardness, electrical conductivity, and water vapor permeability of PS/0.3 wt % c‐MWCNT/3 wt % sN‐LDH nanocomposites over PS/0.3 wt % c‐MWCNT, making use of the synergistic effect of c‐MWCNT coupled with sN‐LDH on polystyrene. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46513.     

Mechanical,thermal, and conductivity performances of novel thermoplastic natural rubber/graphene nanoplates/polyaniline composites

Conventional polymer blending has a shortcoming in conductivity characteristic. This research addresses the preparation of conductive thermoplastic natural rubber (TPNR) blends with graphene nanoplates (GNPs)/polyaniline (PANI) through melt blending using an internal mixer. The effect of PANI content (10, 20, 30, and 40 wt %) on the mechanical and thermal properties, thermal and electrical conductivities, and morphology observation of the TPNR/GNPs/PANI nanocomposites was investigated. The results showed that the tensile and impact properties as well as thermal conductivity of nanocomposite had improved with the incorporation of 3 wt % of GNPs and 20 wt % of PANI as compared to neat TPNR and reduced with further increase of the PANI content. It was observed that the GNPs and PANI acted as a critical component to improve the thermal stability and electrical conductivity of the TPNR/GNPs/PANI nanocomposites. The most improved conductivity of 5.22 E-5 S/cm was observed at 3 wt % GNPs and 40 wt % PANI. Variable-pressure scanning electron microscopy micrograph revealed the good interaction and distribution of GNPs and PANI within TPNR matrix at PANI loadings lower than 30 wt %. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48873.     

Titania-doped multi-walled carbon nanotubes epoxy composites: Enhanced dispersion and synergistic effects in multiphase nanocomposites

Multi-walled carbon nanotube-epoxy composites are modified with titania nanoparticles in order to obtain multiphase nanocomposites with an enhanced dispersion of carbon nanotubes. The dispersion is monitored using rheological and electrical conductivity measurements. An increase in dispersion quality can be correlated to an increased storage shear modulus of the uncured suspensions and to a decreased electrical conductivity in the bulk nanocomposite. The newly formed microstructure is revealed using transmission electron and optical microscopies. Due to chemical interactions between both types of nanoparticles an attractive potential is generated leading to a significant rearrangement in the particle network structure. Besides an enhanced dispersion, the hybrid structure leads to synergistic effects in terms of the glass transition of the nanocomposites. Although a decrease of the glass transition temperature (T_g) is observed for the nanocomposites containing only one type of filler, the combination of titania and carbon nanotubes into a hybrid structure reduces the decrease of T_g, thus demonstrating the potential of such hybrid structures as fillers for multi-functional epoxy nanocomposites.     

Preparation and properties of cyclic olefin copolymers multiwalled carbon nanotube nanocomposites

Nanocomposites of cyclic olefin copolymer (COC) and two types of multiwalled carbon nanotubes (MWCNTs) with different aspect ratios were prepared. The morphology, thermal behavior, and electrical conductivity of the nanocomposites were investigated by scanning electron microscopy, differential scanning calorimetry, thermal gravimetric analysis, and the DC conductivity measurement. It was found that the developed nanocomposite preparation method resulted in good nanotubes dispersion in the polymer matrix for both types of MWCNTs. No appreciable differences in glass transition temperatures were observed between the pure COC and nanocomposites. On the other hand, CNTs significantly improved the thermo‐oxidative stability of the COC. The nanocomposites showed significant delay in onset of degradation and the degradation temperature was ～ 40°C higher than that of the pure COC. The nanocomposites also showed substantially higher DC conductivity, which increased with the nanotube concentration and aspect ratio. An increase of DC electrical conductivity over 10⁹ times can be achieved by the addition of 2 wt % CNTs. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Advance polymeric carbon nanocomposite films with enhanced thermo‐mechanical properties

The homogenous nanocomposite films of UV/O₃ oxidized multiwall carbon nanotubes (MWCNTs) subsequently modified with aniline moiety were synthesized with polymethylmethacrylate (PMMA) through free radical polymerization. The phenylamine functional groups present on the surface of MWCNTs providing an anchoring sites for deposition of Ag metal nanoparticles (NP).The in situ free radical polymerization of MMA in the presence of these well dispersed nanotubes gave a new class of radiation resistant nanocomposite films. The synthesized materials were characterized by FT‐IR, TGA, TEM, EDX, TC, DMA, universal testing machine, and optical microscopy to ascertain their structural morphologies, thermal stability, and mechanical strength. The microscopic and structural properties reflect the homogenous mixing of modified MWCNTs in polymer matrix contributing in enhancement of thermal stability, thermo‐mechanical strength, glass transition temperatures, and thermal conductivity of nanocomposites even at 0.25 wt% addition of modified nanofiller. Thermal and thermo‐mechanical behavior of pre‐ and post‐UV/O₃ irradiated nanocomposite films have been compared with neat polymer. The results revealed that modified nanofiller network can effectively disperse the radiation and has a dramatic reinforcement effect on the nature of degradation of PMMA matrix. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Transparent conducting films based on nanofibrous polymeric membranes and single‐walled carbon nanotubes

Transparent and electrically conducting films were fabricated using a novel and simple method in which single‐walled carbon nanotubes (SWCNTs) adsorbed onto bacterial cellulose membranes were embedded into a transparent polymer resin. The bacterial cellulose membranes consisting of numerous nanofibrils were found to play important roles in this process. The bacterial cellulose membranes impart optical transparency to the nanocomposites due to the size of the materials during the synthesis of the nanocomposite using a transparent polymer resin. The membranes play a secondary role as a template for depositing uniformly dispersed SWCNTs. This results in not only electrically conducting pathways but also prevents interference from the transmittance of optically transparent nanocomposites. Transparent conducting films with a wide range of transmittances and surface resistances could be obtained by controlling the immersion time and SWCNT concentration in the SWCNT dispersions. A transparent conducting film with a transmittance and surface resistance of 77.1% at 550 nm and 2.8 kΩ/sq, respectively, was fabricated from a 0.01 wt %. SWCNT dispersion for an immersion time of 3 h. In addition, the transparent conducting films were quite flexible and maintained their properties even after crumpling. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

In situ polymerization of ethylene with functionalized multiwalled carbon nanotubes using a zirconocene aluminohydride system in solution

This study reports nanocomposite synthesis based on high-density polyethylene with carbon nanotubes through in situ polymerization by coordination, and the use of an aluminohydride zirconocene/MAO system as a catalyst. Nanocomposites of linear polyethylene exhibit higher molar masses than pure high-density polyethylene synthesized under similar conditions; where multiwalled carbon nanotubes (MWCNTs) acted as nucleating agents, shifting the crystallization temperature to higher values than neat high-density polyethylene. Well-dispersed MWCNTs in the HDPE matrices of the obtained nanocomposites are observed by SEM, where most of the nanocomposites showed an improvement in their thermal stability and electric conductivity, besides it is possible to obtain nanocomposites containing up to 41 wt% of nanofiller in the polymeric matrix. The aluminohydride complex n-BuCp₂ZrH₃AlH₂, activated with MAO at Al/Zr ratios of 2000, produced homogeneous HDPE/MWCNT composites under in situ polymerization conditions, at 70°C and 2.9 bar of ethylene pressure, with minimal residual alumina in the HDPE matrix.     

Low electrical conductivity threshold and crystalline morphology of single-walled carbon nanotubes - high density polyethylene nanocomposites characterized by SEM, Raman spectroscopy and AFM

The electrical conductivities (σ) of nanocomposites of single-walled carbon nanotubes (SWCNTs) and high density polyethylene (HDPE) have been studied for a large number of nanocomposites prepared in a SWCNT concentration range between 0.02 and 8 wt%. The values of σ obey a percolation power law with an SWCNT concentration threshold, p_c = 0.13 wt%, the lowest yet obtained for any kind of carbon-polyethylene nanocomposites. Improved electrical conductivities attest to an effective dispersion of SWCNT in the polyethylene matrix, enabled by the fast quenching crystallization process used in the preparation of these nanocomposites. Characterization by scanning electron microscopy (SEM) and Raman spectroscopy consistently points to a uniform dispersion of separate small SWCNT bundles at concentrations near p_c and increased nanotube clustering at higher concentrations. Near p_c, high activation energies and geometries of long isolated rods suggest that electron transport occurs by activated electron hopping between nanotubes that are close to each other but still geometrically separate. The degree of SWCNT clustering given by Raman spectroscopy and the barrier energy for electrical conductivity are highly correlated. The nanotubes act as nucleants in the crystallization of the polyethylene matrix, and change the type of supermolecular aggregates from spherulites to axialitic-like objects. The size of crystal aggregates decreases with SWCNT loading, however, in reference to the unfilled polyethylene, the three-dimensional growth geometry extracted from the Avrami exponents remains unchanged up to 2 wt%. Consistency between SEM, Raman and electrical transport behavior suggests that the electrical conductivity is dominated by dispersion and the geometry of the SWCNT in the nanocomposites and not by changes or lack thereof in the HDPE semicrystalline structure.     

Effect of crosslink density on thermal conductivity of epoxy/carbon nanotube nanocomposites

The effect of the polymeric crosslink density on the thermal conductivity of an epoxy nanocomposite was investigated by adding two different diamine‐functionalized multiwalled carbon nanotubes (diamine‐MWNTs) to the epoxy resin as co‐curing agents and conducting fillers. Tetramethylenediamine (TMDA)‐MWNTs resulted in an epoxy nanocomposite with a higher crosslink density than octamethylenediamine (OMDA)‐MWNTs. Interestingly, epoxy/TMDA‐MWNT nanocomposites under 1.5 wt % nanotube concentration, showed a higher thermal conductivity than an epoxy/OMDA‐MWNT nanocomposite with the same concentration of nanotubes. In contrast, for higher diamine‐MWNT concentrations (over 2.0 wt %), the thermal conductivity of the epoxy/OMDA‐MWNT nanocomposite was higher than that with TMDA‐MWNTs. We observed that for low MWNT concentrations, where a percolating network was not formed, a high crosslink density enhanced the thermal conductivity via phonon transport. However, for high MWNT concentrations, a high crosslink density hinders the formation of a percolating network and lowers the thermal conductivity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44253.