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Researchers are devoted to developing dielectric elastomers (DEs) with excellent electromechanical properties as an artificial muscle material. The authors report a new class of semi‐interpenetrating network (semi‐IPN) composites that contains siloxane‐modified linear polyurethane (PU) and silicone rubber through reasonable design of polymer structure. The organic‐filler copper phthalocyanine (CuPc) is chemically grafted into the semi‐interpenetrating network as a cross‐linking point and exhibits excellent dispersibility in the matrix. The various properties of the obtained composite films are also evaluated. The dielectric constant (8.65 at 1 kHz) and maximum actuation strain at 30 MV m−1 (5.32%) are significantly higher than those of semi‐IPN composites.

In recent years, polymeric insulators have been increasingly used for high voltage overhead transmission lines. The industry has replaced the insulators from ceramic to polymeric due to its lightweight and hydrophobic materials, not to mention the performance against pollutant contamination. In this study, an analysis of two 70 kV silicone rubber insulators is performed. The insulators had been in service for 30 years on transmission networks in volcanic area, exposed to intense UV solar radiation in midday, but also high precipitation occur throughout the year. The urge to understand better of polymeric aging behavior is important to improve the quality of the polymeric type insulators. In this study, these aged samples were then compared with virgin samples to identify the endurance and quality of polymer material. The surface deterioration and the change of chemical content were evaluated using advanced techniques, including Spectroscopy and Scanning Electron Microscopy (SEM), Energy-dispersive X-ray Analysis (EDX), Thermo-Gravimetric Analysis (TGA), and Fourier Transform Infrared (FTIR). Meanwhile, the hydrophobic and visual inspection were also conducted. The hydrophobicity was evaluated by measuring the contact angle and assessed using IEC62073. The aged samples are categorized as hydrophobic class 1 due to the angle value of more than 60o. Physicochemical results showed that the aged sample compared with the virgin simple did not differ significantly given that the aged samples have been in-service for 30 years. Based on TG/DTA result, the percentage difference of weight loss between virgin and aged sample only lower than 4%. Then, from EDX result, the atomic percentage differences of C and O component compared with virgin sample are 4%-10%. Furthermore, the FTIR spectra indicates a normal aging condition of the silicone rubber, the difference in peak value of Si-(CH3)2 and OH compared with virgin sample is 10%.

In this paper, the effect of adding aluminum trihydrate (ATH) on electrical (including dielectric constant, dielectric loss and strength, volume and surface resistivity) and hydrophobic properties of two-part room temperature volcanized (RTV) silicone rubber resin coatings were investigated. For this purpose, the RTV-ATH nanocomposite was made by physical mixing and its electrical and hydrophobic properties were compared with those of pure RTV. The results showed an increase in the dielectric constant (from 3.11 to 4.13), the dielectric loss (by ~ 0.06) and the dielectric strength (by ~ 4 KV/mm) of the RTV-ATH composite compared to the pure RTV. Moreover, ATH increased volume resistivity and reduced the surface resistivity of composite coatings. On the other hand, by spraying of coatings, no improvement in the hydrophobicity class of composite coating compared to pure RTV was observed and both samples were standardized in the HC2 standard class. Structural analysis of samples was performed by X-ray diffraction, optical microscopy and scanning electron microscopy and the presence of the main phases in them was confirmed.

In this paper, the silicon rubber nanocomposites samples cut from the composite insulators operating in high humidity and high temperature areas for 0–13 years were taken as the research object. In accordance to previous research experiences, test methods such as static contact angle method, hardness test method were employed to investigate the changing law of lifespan prediction parameters with operating time. Based on test results, some lifespan prediction parameters significantly correlated with operating time were filtered by means of correlation calculation. On this basis, a prediction method which can be used to determine the operating time of the nanocomposites was proposed based on BP neural network. Test results indicate that lifespan prediction parameters including HC, θ, A, T, H, XO were significantly correlated with the operating time of the insulation material from composite insulator, and these parameters can be used to characterize the aging degree accurately. Besides, due to the high accuracy in experimental verification, the lifespan prediction method proposed in this paper can be used to determine the operating time of composite insulators from transmission lines in future research.

Nanocomposite made by blending nano-montmorillonite (MMT) and Silicon Rubber (SR) for mechanical and tribological performance is explored in this work. Different configurations of MMT/SR nanocomposite, with 0, 0.5, 2 and 5 wt % of MMT are manufactured by two roll mixing methods. Noticeable improvement in the mechanical and tribological performance is observed, which is also justified by a morphological study of fractured and wear surfaces through SEM. Two percent of MMT loading is found to be the optimum content that shows excellent performance compared to other compositions. The performance improvement can be linked to the good interfacial interaction between the MMT and SR. Statistical modeling through ANOVA is carried out for tribological performance, which reveals the influence of load on the coefficient of friction (COF) and the influence of sliding distance on the wear rate.

In order to solve the thermal aging problem of silicone rubber insulation layer of 220 kV integral prefabricated cable joints, the mass loss and thermal gravimetric (TG) were tested. The thermal aging mechanism of thermal degradation reaction of silicone rubber molecular chains was analyzed by gel content test and infrared spectrum test (IR). The results showed that the cross-linked network of the molecular chain structure gradually deteriorates, resulting in the increase of mass loss rate and the decrease of thermal stability. The results also showed that the increase of dual peak of differential thermal weight (DTG), the decrease of initial decomposition temperature and the remaining mass. With increasing aging temperature and aging time, the aging would be accelerated. These properties could reflect the degree of thermal aging of silicone rubber insulation layer. The results could also provide theoretical support for the preparation, operation and maintenance for silicone rubber cable joints.

The vulcanising response and mechanism of the silicon rubber embedded polyarylacetylene prepolymers (PAAP) were investigated to determine the proper vulcanising conditions that could be used to obt...

Technological aspects of modifying the operational characteristics of cold cured silicate rubbers have been developed. The effect of chromium oxide on the resistance of cold-curing silicone compounds to thermal aging, as well as on the physic mechanical properties and dielectric characteristics has been studied. The various content of ultrafine chromium oxide in cold-cured silicone compositions has been investigated, it’s optimal content in an amount of 2 - 5 mass at 100 mass, including low molecular weight rubber. Chromium oxide has been proven to improve the thermal stability of cold-cured silicone compositions. The manufacturing technology and component composition of the composition with high performance.

In recent years, composite insulators have been widely applied in transmission lines; however, deterioration of insulation properties caused by aging may cause power supply’s large-scale outage and badly impact the social economy development. Therefore, in this paper, an entirely new method for evaluating aging properties of silicon rubber for composite insulators based on microscopic images was proposed. The microscopic images were collected by portable digital microscope-B011, and defective area proportion (k) was extracted by calculating and comparing the defective area pixel with the background pixel. Thus, the salt fog flashover experiments were conducted in a multifunction artificial climate chamber to indicate aging properties of silicon rubber material; then, the equations for calculating silicone rubber flashover voltage (U50) by k were established. The value of U50 can even decrease by 57.3% with the increase in the value of ${k}$ . Moreover, a complete aging evaluation procedure of silicone rubber composite insulators was obtained. Taking a city as an example, the critical failure ${k}$ ( $k1=19.6$ ) value of composite insulators in the area was obtained. Finally, the future research directions of this paper were clarified; besides, future usage scenarios of this paper were clearly displayed.

In this research work, we develop a prototype that is able to convert mechanical strain into an electrical signal. To reach this scope, we evaluated the electrical properties of a thermally anneale...

In recent years, the research on magneto-rheological elastomer sandwich structures has increased due to the adjustable properties by varying the magnetic field. However, the study is mainly focused on the theoretical analysis of the magneto-rheological elastomers MRE sandwich plates. In this works, the numerical and experimental investigation on the vibration response of MRE sandwich plates has been conducted. The composition of the iron particles and silicon rubber varied with 30/70, 40/60, 50/50, 60/40, and 70/30% by its weight percentage, respectively. According to the finite element analysis, the magnetic field produced was 0.6, 0.9, and 1.3 T with 2, 4, and 6 mm of the gap between the magnet and MRE composites. The natural frequency and stiffness of the MRE sandwich structured plates was 19.68–23.97 Hz, and 152.6–23.97 N/m, respectively for 0.6, 0.9, and 1.3 T of the applied magnetic field. It is concluded that by increasing the magnetic fields, the stiffness of the material can be changed. This work will contribute to the understanding of the properties of the MRE in the sandwich structures application.

A new kind of cleaning agent for aging insulators in power grid was reported, which can recover its hydrophobicity and insulation performance. The effects of different nonionic surfactants and repairing agents contents on the surface tension, washing efficiency, insulator contact angle, post washing hydrophobicity, post washing loss and transference of hydrophobicity were investigated. Experiments show that the cleaning efficiency is best when the nonionic surfactants content is 3%, and the average contact angle of the insulator after washing is about 126°. When the content of the repairing agent is 11%, its performance is the most superior in all aspects, and its hydrophobicity is the best, which can reach the HC1 level.

Surface tracking and erosion is an irreversible degradation occurring on the insulator surface, and this can ultimately lead to failure of the insulator. Polymeric materials such as silicone rubber have many advantages; including a superior hydrophobic surface. However, polymers are exposed to ageing and degradation resulting from electrical and environmental stresses. The rotating wheel dip test is adopted to conduct a comparative study of surface conduction on the two insulators. A conventional design has been selected and compared with insulators having textured surface. Monitoring of the shed surface and insulator trunk using an IR camera were carried out to assess the temperature distribution along insulator profiles. A spatial analysis was also performed to identify key features of the two designs. Localised surface conductance measurements are proposed in this study. This helps to understand and distinguish the trends of conductance and its distribution on each surface, helping to predict the future surface degradation associated to each design.

In this work, expanded graphite/paraffin/silicone rubber composite phase-change materials (PCMs) were prepared by blending the expanded graphite (EG), paraffin wax (PW) and silicone rubber (SR) matrix. It has been shown that PW fully penetrates into the three dimensional (3D) pores of EG to form the EG/PW particles, which are sealed by SR and evenly embedded in the SR matrix. As a result of the excellent thermal stability of SR and the capillary force from the 3D pores of EG, the EG/PW/SR PCMs are found to have good shape stability and high reliability. After being baked in an oven at 150 &deg, C for 24 h, the shape of the EG/PW/SR PCMs is virtually unchanged, and their weight loss and latent heat drop are only 7.91 wt % and 11.3 J/g, respectively. The latent heat of the EG/PW/SR composites can reach up to 43.6 and 41.8 J/g for the melting and crystallizing processes, respectively. The super cooling of PW decreased from 4.2 to 2.4 due to the heterogeneous nucleation on the large surface of EG and the sealing effect of the SR. Meanwhile, the thermal conductivity of the EG/PW/SR PCMs reaches 0.56 W&middot, m&minus, 1&middot, K&minus, 1, which is about 2.8 times and 3.73 times of pure PW and pristine SR, respectively. The novel EG/PW/SR PCMs with superior shape and thermal stabilities will have a potential application in heat energy storage and thermal interface materials (TIM) for electronic devices.

Silicone rubber has good heat resistance, but its mechanical properties are poor. To improve the mechanical properties of the silicone rubber, the carbon fiber / silicone rubber composites were prepared in this paper, in which the silicone rubber was used as the matrix, the high-performance carbon fiber (CF) treated with coupling agent is used as the reinforcement. The best composite formulation, the types and content of coupling agent are determined by testing mechanical properties of the composites. The morphology structures of the composites were observed by scanning electron microscope (SEM), the compatibility between carbon fiber and silicone rubber was studied by infrared spectrum analysis (IR), dynamic thermal mechanical analysis (DMA) and X-ray photoelectron spectroscopy (XPS). The results show that the best composite formulation is silicone rubber of 100 phr, carbon fiber of 12 phr, coupling agent KH550 of 2.5 phr. The best first curing conditions are at 175 ∘C under 10 MPa for 30 min, the postcuring conditions are at 200 ∘C for 2h. The compatibility between carbon fiber treated with KH550 and silicon rubber is the best by SEM, IR, DMA and XPS analysis, and confirm that the coupling agent KH550 plays a compatilizer role in the preparation process of the carbon fiber/silicone rubber composites.

Composite insulators in valve tower of UHVDC converter station withstand combined ac-dc voltage. The flashover performance of silicone rubber under combined voltage is investigated in this paper. The voltages on the post insulator of valve tower under different operating conditions are simulated in PSCAD/EMTDC, and the harmonic components of the voltages are analyzed. The simulation results indicate that the ac frequencies of the voltage on the post insulator are mainly 50 Hz, 3n and 6n±1 times harmonics. The flashover voltages of silicone rubber under different combinations of ac and dc voltages are tested, including different single frequency ac voltages superimposed on different dc voltages, and different combined harmonic voltages superimposed on different dc voltages. The test results indicate that different ratios of dc voltage to ac voltage and different percentages of harmonics have various influences on the flashover voltage of silicone rubber. Moreover, argon atmosphere pressure plasma jet (Ar APPJ) is applied to modify the surface of the silicone rubber under different modification times and voltages. The flashover voltages and the surface morphologies of the silicone rubber before and after surface modification are compared. Surface modification by Ar APPJ can improve the surface resistivity of the silicone rubber significantly, and the flashover voltage also increases.

Triboelectric nanogenerator (TENG) is favorable for harvesting adaptable and complex biomechanical energy in our daily life. Here, silicon rubber/expandable microsphere TENG was achieved by spin-coating a mixture of expandable microspheres and silicon rubber on a flat plate with conductive fabric. Furthermore, self-made flexible TPU/MWCNTs electrodes replaced commercial conductive fabric to make TENG more adapt to skin of human body. Finally, the optimized TENG in this work demonstrates energy harvesting capabilities and can be applied in self-powered sensor systems and provides new dimensions for biomechanical energy harvesters and wearable self-powered electronics.

Experiments to know themal conductivities of silicone rubber composite were conducted. The sillicon rubber was mixed with coconut shells charcoal powder with weight variations. The weight presentage variations were 0, 10, 20 and 30%. Increasing the weight persentage was expected to increase the thermal conductivity of the composite. The speciment size was 50 mm x 50 mm x 5 mm. The speciments were tested according to the conduction heat transfer mode. To make sure that the temperatures were steady, the experiments were performed for about 6 hours. The results indicated that increasing the weight presentage raised the composite thermalconductivities. At 0% of wight, the composite had a thermalconductivity of 0.157 W/m°C, at 10%, 20% and 30% of weight compositions; the composite had thermal conductivities of 0.461 W/m°C, 0.58 W/m°C, and 0.73 W/m°C respectively.

The use of medium voltage cable joints is mandatory when dealing with power cable faults and the installation of new lines. However, such an accessory is among the top causes of faults among the grid. To this purpose, one of the quantities monitored to understand the causes of such faults is the interfacial pressure between the insulating layers of the cable joint. In this work, the interfacial pressure between Cross-linked polyethylene (XLPE) and silicon rubber has been evaluated when the cable joint experiences thermal cycles. From the results, the pressure variation caused by the thermal cycles is demonstrated. Such a phenomenon may be connected to the generation of voids and weak spots that accelerate cable joint ageing. Therefore, proper comments and conclusions are drawn.

An effort to reduce the overhead line outage due to encroachments like trees and kites, by covering the conductor with silicone rubber has been proposed. Models have been developed to simulate the ampacity and the sagging of conductor before and after the addition of silicon rubber cover. The model represents a 240mm2 ACSR (Aluminum Conductor Steel-Reinforce)-Hawk conductor with thicknesses of the cover of 4, 5, and 6 mm. As a result, the addition of silicon rubber can reduce the ampacity up to 17%, and the height of the sagging increases by 38%.

Hydrophobicity and flashover strength are important properties of outdoor insulators, especially in the tropic region, which have high pollution and high intensity of rainfall. This study examines the impact coal fly ash as a micro filler on static hydrophobicity and DC dry flashover strength of the silicon rubber. The used material is XLR silicon rubber, and coal fly ash (CFA) micro filler. Samples were grouped according CFA filler loading, which consists of six groups CFA filler loading. The result shows that the addition of CFA micro filler affects surface resistivity, the hydrophobicity, and flashover strength of silicon rubber. The hydrophobicity which is presented by contact angle increases with the increasing of filler loading. However, in high filler loading, the hydrophobicity tends to decrease. The similar trend occurs on flashover strength and surface resistivity.

With the purpose of understanding more and more the causes of fault for MV cable-joints this paper deals the interfacial pressure vs. temperature issue. By starting from results obtained by the authors in the field of cable- joints, firstly a test bed for pressure measurements is developed and characterized. Afterwards temperature test cycles have been defined to measure how temperature affects the interfacial pressure (XLPE/Silicon rubber) inside the cable-joints. Presented results confirm the accuracy of the developed setup and the pressure vs. temperature behaviour of two different cable-joints.

In this study, we propose a novel cantilever structure integrated with a high-sensitive and -reliable crack sensor that monitors the contractile behavior of cardiomyocytes in media. Si rubber with excellent performance in cell adhesiveness was used as the cantilever material. The proposed crack sensor formed on the Si rubber cantilever is chemically bonded with the PDMS thin layer to produce a sandwich structure. The protection layer greatly improves the reliability and stability of the crack sensor in the electrolyte solution. The high-sensitive crack sensor stably measures the contractility of cardiomyocytes without changing a gauge factor for up to 26 days.

To investigate the superhydrophobic properties of different surface textures, nine designs of textures with micro-nanostructures were produced successfully using the laser engraving technique on the surfaces of composite insulator umbrella skirt samples made of silicon rubber. The optimal parameters of the texture designs to give rise to the best hydrophobicity were determined. The surface morphology, abrasion resistance, corrosion resistance, self-cleaning and antifouling property of the different textured surfaces as well as water droplets rolling on the textured surfaces were studied experimentally using a contact angle meter, scanning electron microscope, three-dimensional topography meter and high-speed camera system. It was found that the diamond column design with optimal parameters has the best superhydrophobicity and overall performance. The most remarkable advantage of the optimal diamond column design is its robustness and long-term superhydrophobicity after repeated de-icing in harsh conditions. The reported work is an important step towards achieving superhydrophobic surface without coating for outdoor composite insulator in practical applications.

In this work, the effects of magnetic field induction on electrical and electromagnetic shielding properties of conductive silicon rubbers (CSRs) filled with Ni-coated carbon fibres (Ni/CFs) have been investigated. When the magnetic field intensity is above the threshold value of 0.10 T during the vulcanisation, it is beneficial to their electrical property that the volume resistivity decreases from 48.7 Ω·cm to 1.57 Ω·cm, owing to the orientation alignment of Ni/CFs in CSRs filled with Ni/CFs (40 phr). Moreover, with the aids of magnetic field induction, the prepared CSRs with lower amount of Ni-CF filler can receive better electromagnetic shielding of 65 dB in 500 MHz–3 GHz, which reduce cost effectively. This vulcanisation process shows promises for various applications in power transmission and transformation industries.

As a composite, the particle/matrix interface may play an important role in the electrorheological (ER) performance of ER elastomers, which has been overlooked in previous studies. In this study, TiO2 particles and silicon rubber were used to prepare ER elastomers. To improve the interfacial bond strength, two coupling agents, 3-(trimethoxysilyl)propyl methacrylate (A174) and triethoxyvinylsilane (VTEO), were used to modify the surface of the TiO2 particles. Particle characterization results illustrate that the coupling agent modified TiO2 particles present little change in morphology but an increase in size with respect to the bare TiO2 particles. Compared with the bare TiO2 particle filled sample, the modified TiO2 particle filled elastomers present bridging structures between the particles and the matrix, enhanced mechanical properties, and a higher dielectric constant, indicating enhanced interfacial bond strength. The viscoelastic properties of the bare and the modified TiO2 particle filled elastomers were tested and compared. The results indicated that the ER performance, including the field-induced storage modulus and the storage modulus sensitivity, can be promoted by improving the bond strength between the TiO2 particles and the silicon rubber.

When rubber is subjected to a load, deformation will occur. Microscopically, the rubber bond structure is transformed from one equilibrium corresponds to the unloaded rubber that corresponds to the loaded rubber. As with any other transformation process, this process will take time. This paper experimentally demonstrates the relaxation time dependence on the mass of load observed at a constant temperature. The experiment was carried out by inserting the fiber sensor was into a silicon rubber bar. As the rubber bar was loaded, the intensity of light coming out of the fiber decreases exponentially with time. It is shown that the relaxation time increases with the increase of mass loaded on the fiber. By knowing this, the results of the fiber sensor can be adjusted according to the time-based review of rubber deformation.

The relationship between the vibration parameters and the dynamic mechanical properties of the rubber material is established through the vibration reduction experiment and the finite element theory of the ZN-35 silicon rubber damper, which provides a new method for the prediction of the wide-band dynamic mechanical properties of the viscoelastic damping material.

In this work, we report a fabrication of oriented carbon fibres/alumina/silicon rubber composites by 3-D printing. The 3-D printed composites possess higher thermal conductivity up to 7.36 W/m K at 12 vol% CFs and 30 vol% alumina loading than that of cast composites (4.22 W/m K) at the same components. The orientation caused by 3-D printing produces a synergism of the thermal conductivity enhancement for CFs and alumina hybrid filled composites. We attribute the synergism to the decrease of thermal interface resistance, while the reduction of thermal interface resistance has a bigger effect on thermal conductivity of CASR composites. This study provides a novel way to obtain thermal conductive composites with orientation, which has a great significance for the development of high-performance thermal conductive products.

In this work, porous media are studied using silicone rubber with glass microspheres as an example. There were investigated three types of silicon rubber samples featuring different concentrations and sizes of microspheres: non-porous silicon rubber, porous silicon rubber with calibrated glass microspheres and porous silicon rubber with glass microspheres having a wide range of sizes. The density of the samples was 0.99, 0.55 and 0.48 g/cm3, accordingly. Investigating spall strength under pulse tension shows that the destruction beginning threshold of the samples in question is quite low. For the non-porous sample, it is around 30 MPa, for the porous ones it is an order of magnitude lower. The spall plate does not come off the sample after the beginning of destruction. The ability of the free surface velocity to change in such a way is typical for materials with a low destruction threshold.

In this research the epoxy/RTVsilicon rubber and unsaturated polyester / RTVsilicon rubber blends were prepared by adding varying weight (3,5, 7,10 and 20)% of (SR ) to either of EP and UPE resins.The aim of research to analyze effect of RTV silicone rubber composition (3, 5, 7, 10 and 20) wt% of the mechanical properties of the epoxy and unsaturated polyester. Mechanical propertiessuch as impact strength, shore D hardness, young modulusand flexural strength were tested.The experimental results showed that the specimensof EP/SR and UPE/SR blends have a maximum values of impact strength (8.13 KJ/m2 and 11.91 KJ/m2) at the addition of 10% SR and 5% SR respectively.Hardness No. decreased slightly when the content of SR increased at a range of 3% to 20% in both of EP/SR and UPE/SR.Also flexural strength decreased rapidly when the content of SR increased at a range of 3% to 20% in both of EP/SR and UPE/SR.

Silicone rubber is often used to obtain replica of surfaces which are hard to study directly. Here we discuss under what conditions engineering stylus measurements can be used to obtain the correct surface roughness from the replica. We also show how thin vertical slices of the silicone rubber can be used to obtain the surface roughness power spectra for the long-wavelength roughness on even very rough surfaces, such as road surfaces, which may be hard to probe directly with standard optical or stylus instruments.

The objective of this study is the investigation of dielectric barrier discharges (DBDs) with the solid plates and the flexible polymer films. A high capacitance with a high dielectric constant and a small thickness is responsible for the discharge of a high plasma current with a low operation voltage, here, the thin flexible polyimide film ensured a high capacitance, and is comparable to the thick solid-plate alumina. In the long-duration test of the dielectric-surface plasma erosion, the solid plates show a high resistance against the plasma erosions, while the polymer films are vulnerable to the etching by the plasma-species chemical reaction. The polymer-film surface, however, was reinforced remarkably against the plasma erosion by the silicone-paste coating.

Composite power station casing like DC wall casing, transformer casing, runs under long term heat conditions. Heat aging plays a major role in the aging phenomena of silicone rubber material, which is always used as composite casing sheds and sheath. Meanwhile, heat aging is also a important research method to manually accelerate the aging process of SiR for laboratory simulation. At present, study about the influence of heat aging temperature and time on the outer insulation properties of different kinds of SiR is still few. In this article, changes of static contact angle, hydrophobicity transfer ability, water classification and hardness of HTV, LSR and RTV under different aging temperature and time were measured. FTIR and XPS were used to analyze the specimen in order to explore the changes in its micro-physicochemical property. The study result shows that with the rise of aging temperature, the static contact angle of HTV and LSR showed a tendency to rise first and fall then. After heat aging, there was obvious decline in the hydrophobicity transfer ability of SiR, and hardness of different kinds of SiR showed a tendency to rise with the addition of aging time. The results of FTIR and XPS shows that for HTV, there was obvious rise in the absorption peak of O-H, but the peak of major elements changed little. For LSR, the absorption peak of major groups changed little, but the peak of O, C and Si declined and moved.

This study aims to evaluate the hydrophobicity of vulcanized silicone rubber coatings at room temperature (RTV SR) with loads of alumina trihydrate (ATH) and nanosilica (NS) in the polymeric silicone rubber matrix, in order to obtain coatings ATH/NS/RTV SR to cover the surface of glass electrical insulators. The coatings were characterized by scanning electron microscopy (SEM), testing in salt spray chamber, loss test and recovery of hydrophobicity. These coatings showed varying sizes of agglomerates and heterogeneous distribution of particles within the matrix RTV SR. In the test in salt spray chamber smaller leakage current values was observed for the insulator coating with the ATH/NS loads. In the loss and recovery of the hydrophobicity test the best result was observed for insulating load RTV SR / 20: 1 (ATH: NS).

Experimental investigation of the dynamic behavior of sandwich beam and an embedded with shape memory alloy (SMA) wires are deliberated. In this study wires composition of Ni 56.2% remaining Ti were used for vibration control. These wires were inserted in sandwich beam with its neutral axis. The wires are embedded along a length of beam and beam is sandwiched between two copper plates. The beam is tested for free boundary condition and observed natural frequency when the stiffness of beam is changed by actuating the wire with electric current. This paper depicts the frequency response of beam due to embedded SMA wires. Effect of SMA wires on natural frequency and damping factor are examined. The maximum frequency is obtained at 1.5 amps after that frequency continuously decreases because of increase in temperature of the beam.

The conductive silicon rubber samples have been prepared in different filler ingredients, the platform is builded for testing the piezoresistive characteristics of conductive silicon rubber when the material is under water pressure and the test methods are designed, the body piezoresistive properties and surface piezoresistive properties under the water pressure within a certain range are studied respectively. The results show that, the sample of 6% acetylene black/2% nanoSiO2 blends exhibit the best piezoresistive performance when the samples are under water pressure, the piezoresistive properties of the material can be improved with the increase of the thickness of the materials (2mm-4mm), and the conductive silicon rubber used for the pressure-sensitive materials of piezoresistive gauge is feasible.

By use of split Hopkinson pressure bars(SHPB) technique with temperature controllers, a kind of silicon rubber is investigated for understanding its dynamic constitutive behaviors at high strain rates (740-1740s-1) and different temperatures (-40℃, 20℃, 80℃). Experimental results show that silicon rubber is strain-rate sensitive and shows viscoelastic characteristics at room temperature. Moreover this kind of silicon rubber is temperature sensitive at the same strain rate, but is not strain-rate sensitive at high or low temperature.

Water droplets on the surface of silicon rubber were investigated under the influence of non-uniform electric fields. Several parameters of water droplets were investigated, such as the positioning of the droplets regarding the electrodes. The most striking conclusion is that the flashover voltage and electric field distribution depends on the positioning of the droplets from the electrodes.

This research is conducted to assess condition of ceramic insulator with and without silicone rubber coating after 5 years naturally aged in Pangandaran coastal area, West Java, Indonesia. Laboratory testing is also conducted by applying voltage 11–50 kV with high humidity salt fog to the insulator and measuring the leakage current. From the data of magnitude and leakage current waveform of the leakage current, the harmonic content was taken to characterize surface condition of insulator. For higher voltage, it was found that the coating significantly reduced the corona intensity. From the result, ceramic insulator coated with silicone rubber has significant effect especially when installed in a coastal area.