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In this study, we attempted to clarify the electrical characteristics of diamond films synthesized by combustion flame and consequently synthesizing a suitable diamond film for use in electronic device applications. When the film contains amorphous carbon, the electrical resistivity (volume resistivity) decreases, i.e., the electrical characteristics of the diamond film worsen. To decrease the content of amorphous carbon in the diamond film, we utilized methods to detect two parameters: optimal equivalent ratio and optimal substrate temperature. These methods can decrease the amount of amorphous carbon effectively, thereby systematically changing the factors influencing the optimal synthesis for improving the film's electrical characteristics. We have successfully developed a method for producing high-quality diamond films with excellent electrical characteristics and high electrical resistivity (1010 to 1013 Ωm) at room temperature.

Natural fibres are a good reinforcing material. Among the various natural fibres, sisal fibre is of particular interest, since its composites have high impact strength besides having moderate tensile and flexural properties compared to other lignocellulosic fibres. Sisal fibre is a promising reinforcement for use in composites on account of its low cost, low density, high specific strength and modulus, no health hazards, easy availability in some countries and renewability. The present work focused on the recent developments in the field of sisal fibre reinforced phenol formaldehyde composites with reference to the properties of sisal fibre, processing techniques, and the physical and mechanical properties of the composites. The mechanical properties of the composites show much improvement by the addition of sisal fibre of optimum fibre length 40 mm and fibre loading 54 wt%. The better fibre matrix interaction is shown by sisal-PF containing 54 wt%. The comparison with other natural fibres shows that sisal fibre is a good reinforcing agent in PF matrix. Flexural strength and impact strength of the composites were examined and are increased with increasing the fibre content. Ageing studies of the composites showed a similar trend to that of un-aged samples. Interestingly, water absorption test results show that composite with 54 wt% fibre loading have good interaction with the matrix and contains less voids. [ABSTRACT FROM AUTHOR]

Large-scale silver nanowires with a length of 30∼90 μm were synthesized by a polyol process. Electronically conductive adhesives (ECAs) were made by adding micro-sized silver flakes and silver nanowires to the polymer composites consisting mainly of epoxy resin, cure agent and catalyst. The volume resistivity of the ECAs was researched as a function of silver filling loading and sintering temperature. The results indicate that the volume resistivity of ECAs first decreases and then increases with the increase of fractions of silver nanowires when the curing temperature is 180 °C. With the increase of curing temperature, the volume resistivity of ECAs decreases. In the condition of the ECAs filled with 65% silver fillers (the ratio of silver micro-sized silver flakes and silver nanowires is 55:10), the volume resistivity of ECAs reaches 6.5×10 −4 and 1.3×10 −4 Ω·cm when cured at 180 and 300 °C, respectively. The dramatic improvement in the conductivity of the ECAs is due to the low-temperature sintering of the silver nanowires at 300 °C. Effect of silver nanowires on the resistivity of ECAs was discussed in terms of the distribution and sintering behavior of silver nanowires and interaction relationship between silver nanowires and micro-sized silver flakes. [ABSTRACT FROM AUTHOR]

A typical isotropic conductive adhesives (ICAs) composed of an epoxy-based binder containing micro-sized silver flakes was prepared and the effects of different curing procedures on the electrical properties of the ICAs were investigated. The results show that there is greater influence of the curing temperature on 55wt% silver loading, the volume resistivity of ICAs decreases to 4.5 ×10 −3 Ω·cm from 5.2×10 −2 Ω·cm cured at 250 and 180 °C, respectively. However, there is almost no effect on the high silver loading. The variations in electrical resistance of the ICAs with 65wt% silver loading was in situ monitored during the curing process, and it is found that the resistance reaches to 1.99 ×10 6 Ω at 180 °C after cured for 27 min, 1.39 ×10 −3 Ω for 40 min, and 18.8 Ω for 60 min and the cooling process has almost no effect on the electrical resistance of the ICAs. The reasons for the dependence of the bulk resistivity on temperatures were also discussed in terms of the dispersing of the silver flakes in ICAs by SEM. [ABSTRACT FROM AUTHOR]

In this study, non-conductive ethylene–propylene–diene monomer (EPDM)/barium titanate (BaTiO3) composites with high dielectric constant and low dielectric loss are prepared. Fourier transform infrared (FT-IR) spectra show the chemical adherence of vinyltrimethoxysiloxane oligomer (SG-Si6490) to the surface of BaTiO3particles. Functionalised BaTiO3particles have better compatibility with EPDM matrix and promote the cure properties of EPDM composites. It is found that when the content of BaTiO3increases to 40 vol.-%, the resistivity, rheological, dielectric and mechanical properties of EPDM/BaTiO3composites change drastically. The dielectric constant of EPDM with 50 vol.-% BaTiO3at 10 MHz is 15, which is 7.5 times higher than that of EPDM control. Meanwhile, the volume resistivity results show EPDM with 50 vol.-% BaTiO3is still non-conductive. As for mechanical properties, the tensile and tear strength of EPDM control increase from 1.45 MPa and 8.73 kN m−1to 10.02 MPa (about seven times higher) and 24.65 kN m−1(about three times higher), respectively. [ABSTRACT FROM AUTHOR]

Gravure is a high throughput printing process, normally associated with speed, quality, and long print runs. It is widely used for printing on shrink films and other substrates. The shrink films, in particular, polyvinyl chloride (PVC) and glycol-modified polyethylene terephthalate (PET-G), are two dominant substrates widely consumed and printed by gravure process. The PVC and PET-G offer different properties which greatly influence the printability. The surface energy of the substrate determines the adhesion and wettability of ink, while electrical properties such as surface and volume resistivity impact electrostatic assist (ESA) performance. The introduction of ESA in gravure further improved the print quality by eliminating dot skips with reduced impression pressure. However, print defects such as print mottle is inevitable. Print mottle occurs due to a discrepancy between substrate, ink, and process parameters which degrade the print quality. These complexities need to be addressed to deliver higher productivity with less print waste. Therefore, the study investigates the effect of process parameters, i.e., substrate type, line screen, air gap (distance between charge bar and impression roller), viscosity, voltage, and speed, and aims to quantify their effect numerically on defect minimization. The Design of Experiments (DOE) was generated for the above-mentioned parameters and analyzed to extract the best combination of process parameters. The optimized setting showed a reduction in solid mottle by 54% and 57% for PET-G and PVC, respectively. [ABSTRACT FROM AUTHOR]

A polypropylene electrode filled with carbon black, graphite, and carbon nanotubes (CNTs) was successfully prepared by sheet extrusion to serve as the bipolar plate for a zinc/bromine redox flow battery. The electrical conductivity, mechanical properties and charge-discharge performance of the carbon plastic composite electrode with various added amounts of CNTs for the zinc/bromine redox flow battery were investigated. The volume resistivity of the carbon plastic composite electrode was 1.12 Ocm when the CNT content was 5 wt%. The voltage efficiency (VE) and the energy efficiency (EE) of the cell stack with 5 wt% CNT were measured to be 80.7% and 73.2%, respectively, during charge-discharge cycling. In addition, the zinc/bromine redox flow battery equipped with the carbon plastic composite electrode with added CNTs had good mechanical strength and chemical stability. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

NTC thermistor powder was made of a Mn, Ni, Fe and Co oxide mixture calcinated at 1050°C / 60 min. The powder was milled in a ball mill down to an average particle diameter of 0.9 μm. Small disc shaped pills of the powder obtained were made by pressing with a pressure of 2.5 MPa. The pills were sintered in the temperature range of 900-1400 °C for 30-240 min. The volume and specific volume resistivity change were measured as a function of sintering conditions. Microstructure development was observed using a SEM microscope. Using the results obtained, optimization of sintering parameters was performed in order to determine optimal electrical properties of the selected thermistor composition.

These days, composite materials successfully substitute the traditional materials due to its various significant applications. This paper examines the influence of fiber orientation and fiber length on electrical properties of PALF reinforced Bisphenol-A composite and explores the potential of using PALF as reinforcing material for electrical applications such as terminals, connectors, motor body cover, industrial and household plugs and circuit boards. The resistance and inductance of resin material is increased by 24.19% and 24.13% respectively after reinforcement of PALF in different orientations and its value increased by 37.93% and 37.81% respectively after reinforcement of PALF in different lengths. Similarly, Capacitance and Dielectric constant of resin material decreased by 19.44% and 19.39% respectively after reinforcement of PALF in different orientations and its value decreased by 27.67% and 27.50% respectively after reinforcement of PALF in different lengths. It can be inferred from this study that the fiber orientations and fiber lengths greatly effects the electrical properties of PALF composite.

The research was planned to test electrical properties of polymer films made from polyurethane cationomers with 0-2 wt.% graphene admixture. The cationomers were synthetized in the reaction of 4,4′-methylenebis(phenyl isocyanate), polycaprolactone diol ( M = 2000), N-methyldiethanolamine, and formic acid. It was found that addition of approx. 2 wt.% of graphene causes the loss of volume resistivity by three orders of magnitude and percolation threshold is already set at approx. 1 wt.%. The frequency characteristic of a real part of permittivity ε′ and imaginary part of permittivity ε″ were measured for the tested films. On the base of Havriliak-Negami equation, parameters of relaxation functions in frequency domain were estimated for samples containing various contents of graphene. The influence of the cationomer phase structure on observed changes of dielectric losses coefficient tgδ in the full-measuring frequency spectrum was discussed. [ABSTRACT FROM AUTHOR]

We investigated the influence of carbon materials on the properties of adhesives. With the aim of the development of conductive and mechanically improved adhesives, different types of multi-walled carbon nanotubes (MWNT), single-layer graphene, graphene nanoplatelets, graphite, and carbon black were dispersed into an epoxy adhesive. For inserting particles within the viscous matrices and to obtain homogenous and stable dispersions, two different methods namely a three-roll mill and a dual asymmetric centrifuge have been compared The results demonstrate that filling epoxies with carbon nanoparticles improves the conductivity differently. Measuring the electrical resistivity of MWNT-filled composites resulted in an electrical percolation starting underneath 0.1 wt.%. Further, with increasing the MWNT content, conductivity sharply increases. In contrast to the MWNT composites, other carbon nanoparticles require a higher filling content to reach similar values. With a filling ratio up to 17.0 wt.% for ACS graphene nanoplatelets 2–10 nm and the filling of 3.0 wt.% with MWNTs from Nanocyl, the lowest volume resistivities have been reached. [ABSTRACT FROM PUBLISHER]

This article reports several conductive greases prepared by ionic liquids (ILs) that are synthesized by mixing lithium tetrafluoroborate (LiBF4) or lithium bis(trifluoromethane-sulfonyl) imide (LiNTf2) in diglyme (G2) and tetraglyme (G4) with appropriate weight ratios at room temperature (RT). The ILs have good solution in poly(ethylene glycol-ran-propylene glycol) monobutyl ether (PAG) and thus can be used as a base oil for preparing grease for steel–steel contacts. The electrical conductive properties of the grease prepared with the mixed oil of PAG plus ILs were evaluated using the DDSJ-308A conductivity tester, GEST-121 volume surface resistance tester, and HLY-200A circuit resistance tester. Combining the free volume with viscosity, the conductivity is inversely proportional to viscosity. The tribological properties were investigated using an MFT-R4000 reciprocating friction and wear tester. The results demonstrated that the prepared greases possess better conductive and tribological properties than the commercial grease with Cu powder as an additive. [ABSTRACT FROM AUTHOR]

To operate power transformers long-term, as well as ensuring their insulating reliability, it is important to study age-related decline in various insulating oil characteristics and the method used to evaluate the same adequately. Previous studies showed that age-related decline in insulating oil characteristics was caused by trace components in oil produced during oxidation degradation. To maintain and manage aged insulating oil rationally, a specific diagnostic method must be studied, based on measurement of the trace components in oil that cause degradation in these insulating oil characteristics. The present study evaluated the sensitivity to detect various components based on the amount of trace components produced in oil during oxidation degradation for field-aged insulating oil for 34 transformers in various degradation conditions. A study was also conducted to evaluate the degradation condition based on the ratio of trace components produced in oil. Consequently, the detection sensitivity levels were in the order of carbonyl value, saponification value, peroxide value, and total acid value. As the ratio of the saponification value ? the so-called final product ? increased, the degradation of insulating oil developed further. With the above study results, methods of evaluating the dissociation property in the preceding study and the breakdown voltage with the degree of water saturation taken into consideration were combined to establish a comprehensive method of evaluating aged oil. This was then applied to field-aged insulating oil as an example, whereupon the need to replace insulating oil could be evaluated. [ABSTRACT FROM AUTHOR]

Tetra Pak packages (Tetra paks) are one of typical paper/plastic/aluminum composites and widely used in soft drinks and dairy product markets. However, after its service life, serious environmental problems generate due to its non-biodegradable nature. In this paper, a novel electromagnetic interference (EMI) shielding board was developed using recycled Tetra paks waste with addition of iron fibers. The influence of fiber loading level, fiber length and number of iron fiber layer within the matrix on EMI shielding effectiveness (SE) and volume resistivity (VR) was investigated. The results indicated that fiber loading level, fiber length and number of iron fiber layer affected EMI shielding properties significantly. SE increased with the increasing fiber loading, fiber length and number of fiber layer, and VR had an opposite tendency. For the board with 5 mm thickness, the percolation threshold of fiber loading was between 0.008 and 0.02 % (weight of iron fiber/weight of Tetra paks). The boards had excellent total EMI shielding performance in range of 9000 Hz-200 MHz and 600-1500 MHz. This value-added product could be used in packaging, construction and other application fields and exhibited both environmental and economic advantages. It also could be considered as a step toward paper/plastic/aluminum composite waste management and preventing municipal solid wastes environmental pollution. [ABSTRACT FROM AUTHOR]

Electrical and mechanical properties of polymer composite materials are investigated through the determination of resistivity and hardness for composites samples. Epoxy composite samples have been prepared with different concentrations of certain inorganic fillers such as; Titanium dioxide (TiO2) and Silica (SiO2), of various size (micro, nano and hybrid) to study the electrical and mechanical behavior. The volume resistivity reaches 3.23×1014 ohm.cm for the micro silica composite. Surface of composite material has been mechanically examined by hardness test. The results show that the resistivity of microcomposites and nanocmposites are increased with the decrease of filler concentration. But the resistivity of hybrid composites is increased with the increase of filler concentration. Maximum hardness value was obtained from hybrid silica composite with 0.1% filler concentration. [ABSTRACT FROM AUTHOR]

Static electricity and formaldehyde pollution are not only severely harmful to ecological environment but also seriously affecting human health. It is of great importance but still challenging to develop an eco-friendly and multifunctional adhesive for electrostatic shielding. Protein adhesives were considered to be an effective substitute for formaldehyde resin adhesives, but show poor water resistance and conductive, limiting their practical applications in many fields, such as antistatic materials and antistatic floors. Therefore, this study aimed to develop a multifunctional adhesive by a facile organic-inorganic hybrid network to enhance the electrostatic shielding for antistatic materials. As we expected, the volume resistivity of the resultant adhesive for antistatic floors is only 2.73 × 108 Ω·cm, which is five orders of magnitude less than that of soybean meal (SM) adhesive and shows excellent electrostatic shielding performance. After experiencing a rapid thermal shock cycle between two extreme temperature conditions for 30 times, the mechanical performance of adhesive still remained stable. Furthermore, the adhesives are not only eco-friendly and non-formaldehyde, but excellent mildew resistance and flame retardancy. This multifunctional SM-based adhesive opens a new way to replace harmful formaldehyde-based adhesives, which have potential applications in the field of antistatic floors. • A high-performance adhesive was prepared by a facile and green organic-inorganic hybrid strategy for electrostatic shielding. • The multiple bonding structures were formed between protein chains and hydroxylated BT nanoparticles. • The adhesive exhibited mechanical stability under two extreme temperature cycling. • This adhesive could be used for antistatic materials with flame retardance and antimicrobial properties. [ABSTRACT FROM AUTHOR]

Anti- and de-icing techniques for the power systems have been attractive topics in recent years. Semiconductive silicone rubber coatings have been considered and applied in a few regions of China. This paper focuses on the problem of selecting semiconductive coatings under different ambient temperatures. In order to select the semiconductive coatings, the volume resistivity of the coatings doped with various carbon black concentrations was first tested. Then a series of icing/anti-icing tests on bottom-coated insulator strings were carried out in a climate room, where their antiicing performance was studied in terms of icing appearance, ice accretion weight, leakage current and surface temperature. The results show that when the ambient temperature is -2, -4 and -6 °C, the coating resistivities required to prevent ice accretion on the insulator strings tested are presented in this paper. [ABSTRACT FROM AUTHOR]

SUMMARY Many kinds of insulating materials are used outside a spacecraft. They include FEP films, polyimide films, and so on, and are used as thermal control materials. These materials are exposed to a charged-particle environment around the spacecraft. Thus then become charged due to charged particles, especially electrons. It has been pointed out that charging of these materials is likely to cause discharges on the surfaces. From this viewpoint, we investigated the charging potential characteristics of 127-μm-thick FEP film, a typical thermal control material, by exposing it to electron irradiation at various energies below 20 keV. In the dependence of the charging potential on the electron energy, we found that the electron energy at which no charge-up occurs is about 2.7 keV. This appears to be the energy at the which secondary electron emission yield becomes unity. This indicates that electron irradiation of FEP film with energies lower than 2.7 keV induces positive charging. From the charge decay characteristics after electron irradiation, the volume resistivity of the film was also obtained as a function of the electric fields in the bulk of the FEP film. [ABSTRACT FROM AUTHOR]

Now that gas insulated switchgear (GIS) for ac systems are becoming increasingly compact as specifications are rationalized, more consideration of their insulation characteristics for residual dc voltage is required. Furthermore, with dc power transmission technology drawing more and more global attention, clarifying the insulation characteristics of GIS for dc voltage is increasingly important. In this paper, to understand the insulation characteristics of epoxy resin, which is widely used for GIS insulating spacers, factors determining the resistivity of the epoxy insulator surface layer under dc voltage were initially investigated on an experimental basis. Consequently, it emerged that the bulk resistance was more dominant than the surface resistance for the dc resistance of epoxy resin due to the dependency of the test sample resistance value on their radius. Since the electric field might be concentrated if some part of this insulator surface layer showed non-uniform resistivity, the influence of the curing agent, one of the potential causes of this non-uniformity, was subsequently investigated with its content as a parameter. As a result, the volume resistivity in the long-term region was likely to decline or vary for epoxy resin containing less curing agent due to the presence of numerous polarized components unreacted with curing agent. In addition, the presence of micro protrusions or similar, if any, on the insulator surface or electrode is considered to cause electrification due to the concentration of electric field on the surface layer. Accordingly, the relationship between their surface roughness and electrification level was investigated using gaps between insulators or an electrode and an insulator facing each other, respectively. Consequently, where the surface roughness of the insulator or electrode was high, a current component with a large damping time constant, considered attributable to electrical charges moving across the gap, appeared after the charging current components and an electrification condition was observed. [ABSTRACT FROM AUTHOR]

A new conducting lyosol with dual conducting fillers was studied. All steps of the processes along with characteristics and mechanisms of the conducting fillers preparation were discussed and investigated systematically. The conducting fillers, silver coated glass microsphere and silver coated graphite powder, were fabricated by electroless plating method. The surface topography and conductivity of the two kinds of conducting fillers were carefully investigated. Scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) results revealed that the coating presented excellent surface topography. When silver content were 25% and 15% respectively, both fillers acquired the best plating quality. Meanwhile, the volume resistivities of two fillers were almost the same. However, neither the lyosol prepared by silver coated glass microsphere nor silver coated graphite powder showed good long term storage stability. By coupling two conducting fillers and thixotropic agents, a new lyosol exhibited better electrical conductivity, superior temperature resistance and excellent long term storage stability. [ABSTRACT FROM AUTHOR]

To operate power transformers long-term, as well as ensuring their insulating reliability, it is also important to study the age-related decline in various insulating oil characteristics and the method used to evaluate the same in an adequate manner. In the present paper, focusing on the oxidation degradation process of insulating oil, an experimental study was conducted on the influence of the hydrophilic and dissociative properties of oxidation degradation products on the insulating oil characteristics. Consequently, it emerged that, in the presence of highly hydrophilic degradation products, the influence of the water content on the breakdown voltage was likely to be less significant because the saturated water content increased. In the presence of oxidation degradation products with dissociation properties, the characteristic dissipation factor and volume resistivity values were likely to decline due to the influence of water content and heating. Based on the above results, the data in preceding studies were organized. As a result, there was a correlation between the breakdown voltage and the water saturation rate (actual water content in oil/saturated water content). In addition, it emerged that the dissociation property of insulating oil could be potentially determined based on correlation between the 80 ?C values of the dissipation factor and the zero-minute values of volume resistivity at room temperature. These results pertain to the evaluation method used to diagnose the degradation condition of actual field-aged oil. [ABSTRACT FROM AUTHOR]

For long-term operation of power transformers, as well as ensuring their insulating reliability, an adequate study must be conducted on the age-related decline in various insulating oil characteristics and the method to inhibit the decline. In the present paper, to inhibit the degradation of insulating oil, a study was conducted on a method of removing the degradation products generated in insulating oil due to aging and the effect of removing these products. Consequently, for simulated degraded oil subjected to heat stress of 10 years old, degraded through the accelerated degradation of new oil, the performance of insulating oil subject to such accelerated degradation was improved through adsorption treatment and short-term improvement was able to be observed. Following reheating after the adsorbent treatment, a long-term improvement effect to prevent the decline in insulating oil characteristics due to degradation was able to also be observed. On the other hand, for the insulating oil aged about 30 years in the field, the effect was less than that for simulated degraded oil equivalent to about 10 years old. The effect of the adsorbent was able to vary depending on the amount used and the degree of insulating oil degradation. Accordingly, volume resistivity, representing the degree of insulating oil degradation, was varied to study the effect of the adsorbent with respect to its amount. As a result, it emerged that, as the amount of adsorbent was increased, the inhibitory effect on degradation increased but the effect was less significant for insulating oil with volume resistivity significantly decreased. Based on these results, it was clarified that, for aged oil with a low degree of degradation, an inhibitory effect on the short- and long-term decline in insulating oil characteristics was able to be obtained through adsorbent treatment. [ABSTRACT FROM PUBLISHER]

To operate power transformers long-term, as well as ensuring their insulating reliability, an adequate study must be conducted on the age-related decline of various insulating oil characteristics and the method to inhibit the same. Accordingly, in the present study, 1,2,3-benzotriazole (BTA) and 2,6-dibutyl-4-methylphenol (DBPC), which are expected to be effective in preventing oxidation degradation, were added to the test oil and an accelerated degradation test was conducted to examine their effect. Consequently, for new oil, an deactivating effect on copper by the addition of BTA was confirmed and the ability to prevent the decline in characteristics caused by the degradation of the dissipation factor and volume resistivity could be observed. For aged field oil, however, the effect was less than that for new oil. Since phenol compounds structurally similar to DBPC may have been present in aged field oil, a study was conducted on the increasing tendency of concentration and saponification value of the former. As a result, it emerged that the presence of phenol compounds inhibited the increase in the saponification value and boosted oxidation degradation inhibition, even if BTA or DBPC had not been added. Based on the above results, it was clarified that, where an oxidation degradation inhibitor was added or structurally similar compounds were contained, an inhibitory effect on the aging of insulating oil could be obtained. [ABSTRACT FROM AUTHOR]

Highlights: [•] Curing temperature has higher correlation in electrical conductivity. [•] MVQ/CPP composite cured at 205°C shows higher conductive. [•] Network structure of composite varied because of curing temperature. [•] Relationship between network structure and conductivity variation was discussed. [•] Variation of mechanical properties of composite was slight. [ABSTRACT FROM AUTHOR]

Nickel-coated graphite particles and two-component silicone-rubber were compounded to form a conductive composite system. The electrical volume resistivity of the composites were examined and compared under constant tensile strains, cyclic heating-cooling, electric field and repeated cyclic tensile strains in order to study the mechanism of electrical conductivity behaviors of the conductive composites under stress, temperature and current. The results showed that a peak value of the electrical resistivity appeared previously and then gradually increasing with increasing tensile strain. The electrical resistivity displayed positive temperature coefficient effect during the temperature increasing and decreasing. Applying 5A direct current to the conductive composites resulted in an increase in the electrical resistance immediately, but no changes were detected under lower currents. Under the repeated cyclic strain, the peak value of the electrical resistivity of each cycle increased with the test cycle. All the electrical resistivity changes were attributed to the conductive networks broken-up and rebuilt in the conductive composites. [ABSTRACT FROM AUTHOR]

Short nylon-6 fiber-reinforced acrylonitrile-butadiene rubber (NBR) composites were prepared, and their dielectric properties such as dielectric constant, volume resistivity, and dielectric loss factor have been studied as a function of frequency at different fiber loadings. The effects of curing systems and bonding agents on the dielectric properties have also been studied. The dielectric constant decreases with an increase in frequency, which is attributed to the decrease in orientation polarization at higher frequencies. The dielectric constant values have been found to be lower for fiber-filled systems than for the gum. Composite samples cured with dicumyl peroxide exhibit a higher dielectric constant than the corresponding sulfur-cured systems. The addition of bonding agents reduces the dielectric constant of the composites. The volume resistivities of the composites increase with the addition of fibers and with the incorporation of the bonding agents. The added fibers and the different bonding agents decrease the dielectric dissipation factor of the rubber matrix. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 32: E90-E102, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20274 [ABSTRACT FROM AUTHOR]