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AbstractThe aging phenomenon of silicone rubber insulators can bring great safety risks for the stable operation of high-voltage transmission lines. To avoid the significant costs and prolonged downtime associated with completely replacing insulating equipment, our research described in this paper proposes a surface repair material for aged silicone rubber insulators using α, ω-dihydroxy-polydimethylsiloxane as the matrix. The material was, after preparation, uniformly applied to the surface of insulators that had been in grid operation for more than 14 years. The chemical structure, elemental composition and surface morphology of the insulator surfaces were characterized both before and after repair. Our research described here also examined the changes in mechanical properties, insulating resistivity, water repellency and adhesion strength of the insulators. The data showed that the functional group types and element contents on the surface of the repaired silicone rubber insulators were restored to those of the new insulators, and the surface and internal cracks were also effectively repaired. Moreover, the water-repellent, mechanical, and electrical properties underwent a notable enhancement. The robust adhesion between the repair material and the deteriorated surface resulted in the formation of a stable and robust adhesive interface. The results demonstrated that the materials created for the purpose of repair in our research had the capability to efficiently enhance the performance of aged insulators. Furthermore, we suggest this study presented a novel path toward addressing the predicament of aging insulation equipment. [ABSTRACT FROM AUTHOR]

The development of polymer composites, considering the environmental issues, is aimed for minimizing the industrial content. New environmental-friendly nanocomposites, based on silicone rubber matrix and different concentrations of natural fiber/chromium oxide fillers, are prepared for the first time. The microstructural analysis confirms the successful obtaining of microfibers after treatment and chromium oxide nanoparticles and the formation of the final composite. The nanocomposites achieved improved physical and mechanical properties due to the dual effect of both fillers and attachment to the matrix. The 1% optimized nanocomposite achieved the highest modulus, dielectric properties, hydrophobicity, and surface stability. The effect of exposure to weathering conditions was studied. The characterization sentence asserts the preparation of a novel silicone rubber nanocomposite with improved properties, along with the environmental impact, regarding the dual effect of natural fiber waste and chromium oxide nanoparticles. [ABSTRACT FROM AUTHOR]

This study investigates the feasibility of fabricating a dynamic foot prosthesis for lower knee amputees using a composite material composed of polypropylene (PP), fresh cow bone powder (FCBP), and silicon rubber (Si). Nine samples with variable compositions of these components were prepared and subjected to mechanical testing to evaluate their compression strength, elongation, factor of safety, impact energy, and energy storage efficiency. The results demonstrated that the innovative composite made up of 68% PP, 18% FCBP, and 14% Si has exhibited the highest foot energy storage efficiency of 67.83%, which is within the standards of 63–100%. Furthermore, the synthesised dynamic foot has obtained excellent mechanical properties and a maximum factor of safety of 2.71. Accordingly, this study proposes that the developed composite material has the potential to be utilised for the fabrication of dynamic foot prostheses, as it offers a set of improved mechanical properties and potentially enhances the mobility and quality of life for lower knee amputees. [ABSTRACT FROM AUTHOR]

Constructing a synergistic effect with different structural fillers is an important strategy for improving the comprehensive properties of polymeric composites. To improve the comprehensive properties of two-component additive liquid silicon rubber (SR) materials used in electronics packaging, the synergistic effect of granular aluminum nitride (AlN) and tubular carbon nanotube (CNT)-reinforced SR nanocomposites was investigated. AlN/CNT/SR composites with different AlN/CNT ratios were fabricated with two-component additive liquid SR via the thermal curing technique, and the influence of AlN/CNT hybrid fillers on the hardness, strength, elongation at break, surface resistivity, thermal conductivity, and thermal decomposition was investigated in detail. With the incorporation of AlN/CNT hybrid fillers, the comprehensive properties of the obtained AlN/CNT/SR composites are better than those of the AlN/SR and CNT/SR composites. The synergistic thermal conductive mechanism of AlN/CNT hybrid fillers was proposed and demonstrated with the fractural surface morphology of the obtained composites. The obtained AlN/CNT/SR composites show promising applications in electronic packaging, where necessary mechanical strength, electrical insulating, thermal conductivity, and thermal stable materials are needed. [ABSTRACT FROM AUTHOR]

Interpenetrating phase composites (IPCs) with porous metal materials as the matrix and polymer materials as the reinforcement, which have a broad application prospect, have both the high strength of metal materials and the high energy absorption capacity of polymer materials. Entangled metallic wire materials are a new type of porous material with damping characteristics, which is an excellent choice for use as the matrix of IPCs. In the present work, a novel entangled metallic wire material–silicone rubber IPC is developed through the vacuum infiltration method with the entangled wire material as the matrix and silicone rubber as the reinforcing element. The mechanical properties (loss factor and tangent modulus) of the as-synthesized composites are characterized through compression tests. More specifically, the effects of key experimental parameters (strain) and material properties (matrix density, wire diameter, and anisotropy) on the mechanical properties of the composites are analyzed in detail. It is found that with the introduction of interfacial friction, the loss factor of the composites becomes higher than those of the pure entangled metallic wire material and silicone rubber; in particular, the tangent modulus is significantly enhanced. The complex structural characteristics of the proposed composite enable the loss factor and tangent modulus to exhibit a nonlinear relationship with the density over a range of displacement values. Moreover, the smaller the wire diameter is, the greater the loss factor of the composites is, while the tangent modulus exhibits the opposite trend. The unique wire contact form and preparation process endow the composites with nonlinear properties in the molding direction as well as pronounced anisotropy characteristics. A novel interpenetrating phase composite is proposed. The composite quasistatic curve is nonlinear with excellent mechanical properties. The improved energy consumption properties are due to the interfacial friction. The increase in wire density greatly improves the elastic modulus of the composite. The composite is anisotropic with a better bearing capacity in the molding direction. [ABSTRACT FROM AUTHOR]

The aim of this study is to examine the durability of composite materials reinforced with carbon fiber and the effects of silicone rubber on the composites' tensile strength, bending, firing, impact, and density. The silicon fiber was mixed with resin using a magnetic stirrer at 250 rpm, with a temperature of 40o C for 30 minutes. Furthermore, the composite production process was carried out using a vacuum infusion method with carbon fiber sheet variations of 6, 8, and 10. Tensile strength shows a proportional increase with the number of carbon fiber layers. Flexural strength indicates the opposite. The impact test was conducted in accordance with the ASTM E 23 standard, the firing test was performed using a 9x19 mm caliber bullet with a distance of 10 m, and the density was found by employing ASTM 792-13. The greatest density was 1,274 grams/cm3, and it was gotten from the sample with 10 fiber layers. Following this, the results of the impact test (Izod) showed that the specimen with 6 layers of carbon fiber had the highest impact strength of 0.040 Joule/mm. While the shoot test results indicated that the composite with 6 layers of carbon had smaller shot holes. There was no significant absorption in the water absorption test. [ABSTRACT FROM AUTHOR]

Flame retardant rubber composites have attracted a great attention during the past decades owing to their irreplaceable roles in complex industrial systems. Large amounts of efforts have been made to improve the flame retardant ability, developing high efficiency flame retardant systems which can reduce the release of heat, smoke and toxic gases while not deteriorate overall properties is becoming more and more important. This review briefly outlines the recent developments of flame retardant natural rubbers, silicon rubbers, some kinds of artificial rubbers and polyurethane elastomer composites, focuses on the design, development, mechanism and applications of advanced high-performance flame-retardant methods. Finally, outlooks the future tendency including more environmental-friendly strategies, higher flame-retardant efficiency and development of multifunctional flame-retardant rubber composites are proposed.

Constructing a synergistic effect with different structural fillers is an important strategy for improving the comprehensive properties of polymeric composites. To improve the comprehensive properties of two-component additive liquid silicon rubber (SR) materials used in electronics packaging, the synergistic effect of granular aluminum nitride (AlN) and tubular carbon nanotube (CNT)-reinforced SR nanocomposites was investigated. AlN/CNT/SR composites with different AlN/CNT ratios were fabricated with two-component additive liquid SR via the thermal curing technique, and the influence of AlN/CNT hybrid fillers on the hardness, strength, elongation at break, surface resistivity, thermal conductivity, and thermal decomposition was investigated in detail. With the incorporation of AlN/CNT hybrid fillers, the comprehensive properties of the obtained AlN/CNT/SR composites are better than those of the AlN/SR and CNT/SR composites. The synergistic thermal conductive mechanism of AlN/CNT hybrid fillers was proposed and demonstrated with the fractural surface morphology of the obtained composites. The obtained AlN/CNT/SR composites show promising applications in electronic packaging, where necessary mechanical strength, electrical insulating, thermal conductivity, and thermal stable materials are needed.

To reduce the damage of external impact on the human body, there are sponges, foams and other cushioning materials on the market at present. However, their preparation process and use cause environmental pollution. It is urgent to develop flexible cushioning materials with lightness, softness, durability, superior performance, environmental friendliness and low carbon emissions as helmet linings and insoles.In this paper, five kinds of warp-knitted spacer fabrics with the same raw materials but different organizational structures were selected as the reinforcing matrix, and silicone rubber was used as the filler to prepare flexible cushioning materials with different filling rates. The compression and cushioning properties were tested and analyzed, and the relationship between the process parameters and properties of the cushioning materials was explored. When the filling rate is 30% and 50%, the flexible buffer material has good elasticity. When the filling rate is 70% and 100%, the flexible buffer material has good compression resistance. Under the same filling rate of different fabrics, the shape of the compression load curve is similar. The load capacity of the flexible buffer material with silicone rubber filling rate of 30%, 50%, 70% and 100% increases as a multiple of the pure fabric. There is a multiple linear regression relationship between the maximum compression and impact load of the flexible cushioning material and the filling rate and the structural parameters of the warp knitted spacer fabric. The process parameters of warp knitted spacer fabrics have different effects on the load performance of buffer materials with different filling rates. When the filling rate is large, the hardness of the flexible buffer material is strengthened and the slow elasticity is weakened. Selecting the highlight zone parameters in the figure can reduce the use of silicone rubber. The filling rate has a significant effect on the cushioning capacity of the flexible cushioning material. A small filling rate can improve the cushioning performance of the warp knitted spacer fabric. The thickness of the warp-knitted spacer fabric has a great influence on the cushioning performance of the flexible cushioning material. The filling rate and thickness parameters can refer to the blue area in the figure to reduce the production cost of the enterprise. In this paper, silicone rubber is filled in the warp knitted spacer fabric, and the influence of filling rate and fabric structure on the performance of the flexible buffer material is investigated. Greenhouse silicone rubber can improve the load bearing capacity and buffering capacity of warp knitted spacer fabrics. With the increase of the filling rate, the load and impact resistance increase exponentially. The filling rate has a great influence on the load capacity of the flexible cushioning material, and the thickness of the warp knitted spacer fabric has a significant influence on the cushioning capacity of the flexible cushioning material. This flexible cushioning material can be applied to the fields of cushioning or protection. The manufacturing process of this flexible buffer material has basically no pollution to the environment and meets the requirements of environmental protection. Flexible cushioning materials have the ability to slow down and impact resistance, which can protect the body and have great application prospects in the fields of protection and buffering. [ABSTRACT FROM AUTHOR]

Entangled metallic wire material–silicone rubber (EMWM–SR) composites with a three-dimensional interpenetrating network structure were manufactured through the vacuum infiltration method with the matrix of entangled metallic wire material (EMWM) and reinforcing element of silicone rubber (SR). Quasistatic compression tests and low-velocity impact tests of the proposed composites were performed, and the deformation model and damage characteristics of the tested EMWM–SR composites were investigated by performing computerized tomography scans and indentation depths. Experimental results show that the stiffness and energy consumption of the EMWM–SR composites are more than twice the sum of those of the individual EMWM and SR in the displacement range of 1.5–4.0 mm. With the increase of loading displacement, the stiffness of EMWM–SR composites increases steadily and the energy consumption increases sharply. Compared with EMWM and SR, the maximum displacement and peak force of the composite materials are decreasing significantly in the low-velocity impact tests. With increasing density, the impact resistance of the composites increases, while the energy absorption decreases. In other words, EMWM–SR 2.6 has better impact resistance but lower energy absorption capacity. The maximum displacement and the peak force increase synchronously with the increase in impact velocity. Interestingly, the composites maintain a high energy absorption capacity at different impact speeds. Furthermore, the energy absorption characteristics of the EMWM–SR composites under low-velocity impact are described in terms of the deformation mechanism of the wires.

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The research progress in dynamically vulcanized polyurethane/silicone rubber thermoplastic elastomer was summarized from the aspects of raw material selection, processing technology and compatibilizer with 20 references.

Abstract Marine biofouling will bring a series of environmental and social problems, which restrict the development and utilisation of marine resources. Therefore, how to prevent biofouling has become a global issue. With the exploration of antifouling methods, bionic antifouling technology with environmentally friendly, broad‐spectrum, and long‐term advantages has gradually attracted people's attention. Inspired by the antifouling strategy of soft coral (Sarcophyton trocheliophorum), the silicone rubber (RTV‐2) with similar elasticity to coral skin was selected as the substrate. The composite structure of the upper transparent layer and the lower porous layer was prepared by simulating the structure of soft coral as the structural factors of the bionic antifouling coatings. Meanwhile, several organic antifouling components with high content contained in soft coral were added to the transparent layer and porous layer, respectively, as the component factors of biomimetic coatings. The bionic antifouling coatings, which are highly consistent with the coral structure, obtained the best antifouling performance under static and dynamic conditions. The above results provide new ideas for the synthesis of environmentally friendly bionic antifouling coatings.

In this work, boron nitride nano sheets (BNNSs) were prepared by exfoliation of h-BNs using mono ethylene glycol (MEG) as a novel exfoliating agent. For comparison, isopropyl alcohol (IPA)/water mixture was also used for exfoliation of h-BNs. It was found that using MEG caused preparing nano layers with higher yield and lower thickness compared to the IPA/water mixture. Thereafter, silicon rubber nanocomposites contained 3 and 5 wt% of pure and exfoliated BNNSs were prepared and evaluated for thermal and electrical performances. It was found that h-BNs and exfoliated-BNs drastically enhanced thermal conduction of SR. The silicon rubber contained 5 wt% of the h-BN and exfoliated-BNs illustrated around 20 times higher thermal conductivities compared to pure SR. Exfoliation of h-BNs had negligible effect on improvement of thermal properties, however, it caused 5.7 and 2.3 times enhancement in the electrical volume resistivity compared to the pristine SR and pure h-BN containing nanocomposite, respectively. Both of the BNNSs caused improvement in the heat dissipation performances of SR matrix, however, the exfoliated one with MEG showed better performances. Based on the results, it was claimed that mono ethylene glycol could improve exfoliation of h-BNs and enhance the performances of silicon rubber.

The characteristics of the shape memory effect of a silicone rubber–titanium nickelide composite material under bending deformation have been studied. It is shown that the critical deformation (), upon reaching which 0.2% of unrecoverable deformation is accumulated in the composite, can reach 36–38% (at = 9% in a reinforcing filler made of titanium nickelide). A method for calculating the mechanical behavior of a composite under bending deformation is proposed. [ABSTRACT FROM AUTHOR]

Silicone rubber (SR)/vinyl-graphene oxide (vinyl-GO) nanocomposites were prepared through the hydrosilylation reaction of silicon hydrogen polydimethylsiloxane (H-PDMS) with vinyl polydimethylsiloxane (vinyl-PDMS), in which vinyl-GO was used as a nano filler. The thermally conductive and antistatic properties of the nanocomposites, and their tensile strength and thermal stability were evaluated. The thermally conductive and antistatic properties increased naturally when the nanocomposites had eight to nine parts of vinyl-GO. The addition of 9 parts of vinyl-GO increased the thermal conductivity to 0.44 from 0.17 W/m−1·K−1 of neat SR and the surface resistance value to 108 from 1014 Ω of neat SR. Vinyl-GO is effective in improving the tensile strength and toughness of the nanocomposites. The tensile strength and elongation at break of the nanocomposites were much higher than that of neat SR, especially for 10 parts of vinyl-GO in the nanocomposite, and the tensile strength was 1.84 MPa and the elongation at break was 314.1%. Additionally, compared with neat SR, the nanocomposites had a much higher thermal stability. For eight parts of vinyl-GO in the nanocomposites, H-PDMS with the selected silicon hydrogen content and vinyl-PDMS with the selected vinyl content could offer an appropriate cross-linking degree that suits the character of GO. When the nanocomposite had eight parts of vinyl-GO, its scanning electron microscope exhibited a monolayer GO with folded, twisted, and local surface folds. However, there was a certain amount of multilayer aggregation of GO for 10 parts of vinyl-GO in the nanocomposite. [ABSTRACT FROM AUTHOR]

With the rapid development in the aerospace field, there is an increasing demand for flexible ablation materials with excellent cyclic ablation property, which attracts more and more attention from researchers all over the world. In this paper, the uniform experimental design method is used to prepare lamellar material filled epoxy modified vinyl silicone rubber (EMVSR) flexible ablation resistant composite materials. The effects of three layered materials (lamella sericite, MoS2, and GO) on the ablation performance and thermal insulation performance of EMVSR materials under cyclic ablation conditions are discussed. In addition, the compressive strength of the composites after ablation and the density of the char layer are tested and analyzed. The test results show that all these sheet materials can enhance the heat resistance and thermal conductivity of the EMVSR composites and GO has the greatest impact. The back‐face temperature of the EMVSR composites after the second ablation is higher than that after the first ablation, and GO can significantly improve the material's heat insulation performance under cyclic ablation conditions. The mass ablation rate of the EMVSR composites after the second ablation is generally greater than that after the first ablation. GO and sericite will reduce the ablation resistance of the materials, while MoS2 will increase the ablation resistance of EMVSR composites. The compressive strength of the char layer and the ablative resistance of the materials are positively correlated with the density of char layer. [ABSTRACT FROM AUTHOR]

Marine biofouling will bring a series of environmental and social problems, which restrict the development and utilisation of marine resources. Therefore, how to prevent biofouling has become a global issue. With the exploration of antifouling methods, bionic antifouling technology with environmentally friendly, broad‐spectrum, and long‐term advantages has gradually attracted people's attention. Inspired by the antifouling strategy of soft coral (Sarcophyton trocheliophorum), the silicone rubber (RTV‐2) with similar elasticity to coral skin was selected as the substrate. The composite structure of the upper transparent layer and the lower porous layer was prepared by simulating the structure of soft coral as the structural factors of the bionic antifouling coatings. Meanwhile, several organic antifouling components with high content contained in soft coral were added to the transparent layer and porous layer, respectively, as the component factors of biomimetic coatings. The bionic antifouling coatings, which are highly consistent with the coral structure, obtained the best antifouling performance under static and dynamic conditions. The above results provide new ideas for the synthesis of environmentally friendly bionic antifouling coatings. [ABSTRACT FROM AUTHOR]

Insulating materials with heat dissipation are urgently required for modern electronic devices and systems. In this study, 4,4-methylene diphenyl diisocyanate was used as the coupling agent, and nano-diamond (ND) particles were grafted onto the surface of carbon fibers (CFs) to prepare CF-ND/silicone rubber (SR) composites. The ND acted as a "bridge" among CFs, which can reduce the interface thermal resistance between CFs because the dot-like ND can increase the interfacial area of CFs, making it easier to form heat-conducting networks between SR. When the content of CF-ND (1:6) was 20%, the thermal conductivity of the SR composite was 0.305 W/(m·K), 69% higher than that of pure SR. The ND between CFs can improve the dynamic mechanical properties by acting as a crack pinhole. In addition, the CF-ND/SR composites also exhibited excellent thermal stability. This work has enormous potential for advanced electronic devices. [ABSTRACT FROM AUTHOR]

In power transmission lines, it is necessary to isolate the inherent voltage parts from each other and from zero potential. An insulator is defined as having a high degree of electrical insulation between the conductors and the brackets. Insulators also allow for mechanical conductivity of the conductor and ground. The presence of a broken insulator can alter the stress distribution. In this paper, the effect of mechanical insulation cracking (chattering) on electric field in two common types of insulators (porcelain and silicone rubber) and electric potential distribution models are analyzed. First, the electric field and electric potential patterns in the solid insulator are examined. In the following, the insulator is assumed to be broken, and the electric field and electric potential patterns for a broken insulator relative to the basic insulator shape are illustrated and compared. The results show that the presence of insulation cracking under dry and environmentally benign conditions affects the stress distribution pattern within and around the insulator. Finally, a comparison between the effect of fracture on the electric field and the potential distribution patterns in different parts of the insulator is discussed in detail. [ABSTRACT FROM AUTHOR]

Lead, the conventional choice for wearable radiation shielding, faces growing health and occupational concerns. This prompts the search for a lighter, more flexible alternative. Nylon 6, prized for its mechanical prowess, emerges as a reinforcement in wearable composites. This study focuses on creating silicon rubber composites using Nylon 6 reinforcement and varying proportions of Bismuth oxide and aluminium fillers. Mechanical Parameters such as Tensile strength and Elongation at break, are studied and the quality of fabrication is assessed using a Scanning Electron Microscope. Studies on various combinations of nylon 6-based silicon rubber with varying percentages of bismuth oxide and aluminium fillers have been studied and radiation parameters have been assessed. TSN-4 (60% wt. bismuth oxide along with 50% wt. aluminium powder) showed the highest tensile strength of 25.13 MPa having 79.3% of elongation at break followed by TSN-1 & TSN-3. The results reveal good mechanical properties as well as satisfactory radiation attenuation properties. The combination of Nylon 6-based with 60% wt. bismuth oxide along with 50% wt. aluminium powder (TSN4) was considered optimal for the energy range from 140 keV to 511 keV with HVL of 2.06 cm, TVL 6.86 cm, and MAC of 0.093 gm/cm2 and also bearing good mechanical properties. Further, the fabricated samples can be compared with the Monte Carlo Simulation method for further improvements in the fabricated composites. The produced composites have the potential to be used as lead-free protective wearables and wearing devices in nuclear medicine following further investigation. • Research focuses on novel nylon-based silicon rubber composites with fillers from 140Kev gamma to 511 Kev Positron range. • 60% Bismuth oxide and 50% Aluminium powder as filler, exhibits excellent mechanical and radiation attenuating properties. • Novel Nylon-6-based silicon rubber composites emerge as a Potential lead-free option for wearable radiation shielding. • Avenues for nanocomposites of bismuth and aluminum additives to enhance radiation shielding advancing technology. [ABSTRACT FROM AUTHOR]

Despite the fact that Pyrovatex is widely used as a commercial flame-retardant, the release of toxic formaldehyde remains a serious problem. Fluorine-based compounds, on the other hand, have been employed to impart hydrophobic textile surfaces, although they are exceedingly costly and poisonous. Based on those difficulties, we describe a simple one-step method for coating electrically conductive cotton-nickel (Cot-Ni) blend fabric providing flame-retardant and water-repellent characteristics. A nickel ribbon was firstly bent around a cotton yarn as a core, and then woven into an electrically conductive Cot-Ni blend fabric, which was created by weaving the cotton-nikel hybrid threads with regular cotton yarns. The conductive fabric was coated with a composite consisting of silicone rubber (RTV) and ammonium polyphosphate (APP). The strong binding of RTV with both APP and cotton fibres increased the flame-retardant action of cotton, according to the findings. As a result, varied concentrations of APP were used in the composite to show that only 100 g/l of APP combined with RTV improved the fire-retardancy. Depending on the concentration of APP, distinct hierarchical morphologies appeared on the surface of the coated Cot-Ni fabrics. RTV also improved the hydrophobic character of the blend surface. Measurements of air permeability, surface roughness, and stiffness were used to investigate the comfort qualities of the coated Cot-Ni blends. Eventually, those multifunctional (Cot-Ni)/RTV-APP textiles might be used in a variety of applications, such as grain storage containers, car seat mats, and firefighters' uniforms. [ABSTRACT FROM AUTHOR]

A study aimed to prepare cellulose-based hydrophobic, lightweight, and flame retardant foam composites. Cellulose was activated by phosphoric acid followed by blending with dolomite clay of different loading ratios. Gelatin/tannin as an adhesive system was used as a binder. A solution of the environmentally friendly silicone rubber (RTV) was applied onto foam samples via spray-coating to improve their water repealing performance, which was explored by investigating both of water contacting angle and wettability time of the coated foam samples. Flammability characteristics, thermal decomposition, surface morphology, and chemical structure of treated and untreated foams were investigated by flammability test, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared. The fire retardancy of foam composites was optimized at low and medium loading of dolomite. Also, the addition of RTV improved the hydrophobicity of composites maintained the fire retardancy of composites with medium loading. [ABSTRACT FROM AUTHOR]

A new nanocomposite superhydrophobic of the RTV (room temperature vulcanized) silicon rubber reinforced with a different percentage of nanosilica was prepared by a two-stage sol-gel route to obtain a superhydrophobic surface coating on high voltage glass insulator, preventing the dust-water droplet from adhering to its surface. The cold spraying technique was utilized to build up a thin nanocomposite superhydrophobic layer on the glass insulator containing different percentages of the nanosilica particles, such as 23 wt %, 33 wt %, and 44 wt % with RTV silicon substrate. The synthesized nanocomposite was analyzed using the contact angle, roughness, adhesion, hardness, and dielectric strength tests. Moreover, the prepared RTV silicon rubber/nanosilica superhydrophobic nanocomposite layer was characterized using the field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and the particle size analysis test. Based on the results, the nanosilica particles were well-incorporated into the RTV silicon rubber, obtaining an excellent homogenous distribution thin layer on its surface, supporting its capability to be a superior superhydrophobic surface. The results reveal that the RTV silicon rubber/33wt % nanosilica was the best as a superhydrophobic behavior with a contact angle reaching higher than 158°± 3; also, a significant change in the dielectric strength was obtained to be 25.5 kV (using a speed voltage of 5.0 kV/s). Importantly, the flashover test was also conducted, and it was found that there was a significant change in the leak current between the coated and uncoated samples. The leak current of the coated sample with a superhydrophobic nanocomposite was reduced to 2.5 mA, while the uncoated sample became 3.2 mA using a voltage load value of 60 kV. The results presented here may improve the nanocomposite material as an antiweathering superhydrophobic thin layer supported by the prepared nano-SiO2 particles against the dust-water droplets which may be adhesive to the high voltage glass insulator. [ABSTRACT FROM AUTHOR]

To further improve the ablation and thermal properties of silicon rubber composite materials, the 3, 13‐divinyloctaphenyl double‐decker polyhedral oligomeric silsesquioxane (DV‐DDSQ) modified additional vinyl‐terminated polydimethylsiloxane (VPDMS) was prepared, and the effect of high silica fiber reinforcement on the ablation properties of VPDMS was investigated. The results show that when 0.8phr DV‐DDSQ was added, the mass residual rate at 800°C of the composites increased from 40.6% to 51.0%. The linear ablation rate (LAR) as well as mass ablation rate (MAR) of the composites of the DV‐DDSQ modified VPDMS, the high silica fiber reinforced VPDMS composite (HSF/VPDMS composite) and the high silica fiber reinforced DV‐DDSQ modified VPDMS composite (HSF/DV‐DDSQ‐VPDMS composite) decreased dramatically compared with raw VPDMS, and it was 16.36%, 35.69%, and 37.17% bring down for LAR and 5.34%, 14.60% and 25.59% for MAR, respectively. The tensile strength and hardness of the DV‐DDSQ modified composites increased by 9.52% and 14.13%, respectively, while the elongation at break decreased by 5.99%, compared with the raw VPDMS. [ABSTRACT FROM AUTHOR]

The problem of the research conceder Inefficiency of the floors of open or closed sports fields in weather conditions such as heat and rain. also, the floors of sports fields are affected by constant pressure on them, which exposes them to damage and shredding. Most of these floors are imported from abroad and there is no Egyptian technology to produce them. The research aims to providing local qualities for sports stadium floors produced with Egyptian technology and using reinforced fillers of banana and glass fibers. In this research, a hybrid superposed material based on polymeric basis was prepared using the hand lay-up method. - 4 silicon rubber samples were produced : The first sample : 50 grams banana fiber whiskers, 1 kg silicon rubber.The second sample: 100 grams banana fibers whiskers, 1 kg silicon rubber.The third sample : 100 grams of fiberglass (1) woven layer, 1 kg of silicon paper.The fourth sample: 200 grams of fiberglass (2) woven layer, 1 kg of silicon paper. The third sample is the ideal sample for the work of the sports stadiums appropriate for the track or field for small sports, due to the increase in the strength by an appropriate amount while maintaining the highest amount of elongation, as it is one of the least samples losing weight and land resistance. These are very suitable qualities for the track and field halls and gymnasium floors, which allows a significant decrease in the percentage of sports athletes injured, and not affected by conditions of weather conditions such as high temperature, cold and rain. The important economic aspect in producing this type of stadium flooring in a simple way and in a pure Egyptian style, as the material of banana fibers was used instead of burning or disposing in a way that achieves an important environmental aspect. The glass fibers are used for reinforcement, which gives a large part of the continuity of the floor with some maintenance. As for the silicon material, it is less expensive than other materials used to cover sports fields.

In this paper, factors affecting the mechanical properties of polymeric granite artificial stone have been investigated. Epoxy resin and three types of additives called Poly ether ether ketone, Silicon rubber, and Nanoclay have been used to make the artificial stone. Unlike previous research on resin alone, this study has been conducted on artificial stone and samples made using these materials. These samples are compared with the control sample and the sample with optimal mechanical characteristics. The method of making artificial stone is that crushed stone blend with resin, and is molded into molds that are defined according to the American Association of Materials and Testing. Samples were made with two percentages of 7.5 and 15 percent to determine the optimum amount of additive. After curing, the sample is subjected to testing. The results obtained from these experiments for artificial stone show that the addition of polyether ether ketone to epoxy resin compressive strength by more than 30%. 7.5wt% of Nanoclay increases more than 6% in compressive strength in epoxy resin. Therefore, the amount of 7.5% by weight of the additive has been selected as the optimum percentage and only this percent is considered in the manufacture of flexural and tensile strength samples. Adding Silicon rubber to the epoxy resin, increases the flexural strength by 7%. Contrary to expectation, Nanoclay reduces flexural strength significantly. By examining the results of the tensile test, it was determined that the addition of silicon to the epoxy resin increased the resistance to 46% . It is concluded that the addition of silicon rubber has been effective in increasing the compressive strength and in increasing the flexural and tensile strength and adding polyether ether ketone.

Development of stretchable wearable devices requires essential materials with high level of mechanical and electrical properties as well as scalability. Recently, silicone rubber-based elastic polymers with incorporated conductive fillers (metal particles, carbon nanomaterials, etc.) have been shown to the most promising materials for enabling both high electrical performance and stretchability, but the technology to make materials in scalable fabrication is still lacking. Here, we propose a facile method for fabricating a wearable device by directly coating essential electrical material on fabrics. The optimized material is implemented by the noncovalent association of multiwalled carbon nanotube (MWCNT), carbon black (CB), and silicon rubber (SR). The e-textile sensor has the highest gauge factor (GF) up to 34.38 when subjected to 40% strain for 5,000 cycles, without any degradation. In particular, the fabric sensor is fully operational even after being immersed in water for 10 days or stirred at room temperature for 8 hours. Our study provides a general platform for incorporating other stretchable elastic materials, enabling the future development of the smart clothing manufacturing.

Rubber magnet merupakan material maju yang dapat dipolarisasi secara magnetis yang tertanam dalam matriks karet lunak. Rubber magnet diaplikasikan sebagai komponen pada pintu atau jendela sebagai pengunci dan sealer, atau sebagai material perekat antara dua komponen, serta sebagai komponen motor listrik DC yang kecil. Penelitian ini dilakukan untuk mengetahui pengaruh komposisi silicon rubber terhadap sifat fisis, mekanik (kuat tarik) dan sifat kemagnetannya atau kekuatan magnet. Rubber magnet dibuat dengan menggunakan partikel magnet Ba-Ferrite (BaFe12O) dan silicon rubber (SR) sebagai perekat dengan komposisi 5%, 10%, 20% dan 30% berat SR. Kedua bahan baku tersebut dicampur hingga homogen, kemudian dibentuk dengan metode tuang. Selanjutnya sampel yang telah dibentuk dalam bentuk lembaran dikeringkan pada suhu kamar selama 2 jam. Karakterisasi sampel yang dilakukan meliputi pengukuran densitas, pengujian kuat tarik, dan kuat medan magnet menggunakan Gauss meter. Berdasarkan hasil karakterisasi bahwa dengan meningkatnya komposisi SR nilai densitas cenderung menurun, namun nilai kuat tarik dan elongasi cenderung meningkat hingga komposisi 20% SR, kemudian menurun pada komposisi 30% SR. Artinya semakin banyak kandungan SR maka fleksibilitasnya cenderung meningkat. Berdasarkan pengukuran kuat magnet menunjukkan bahwa sampel dengan komposisi SR yang semakin meningkat maka nilai kuat medan magnet cenderung menurun. Rubber magnets are advanced, magnetically polarized materials embedded in a soft rubber matrix. They are applied as components in doors or windows as locks and sealers, or as an adhesive material between two components, and as a component of a small DC electric motor. This research was conducted to determine the effect of the composition of silicon rubber on its physical, mechanical (tensile strength) and magnetic properties or magnetic strength. Rubber magnets are made by using magnetic particles Ba-Ferrite (BaFe12O) and silicon rubber (SR) as an adhesive with a composition of 5%, 10%, 20% and 30% by weight of the SR. The two raw materials are mixed until homogeneous and then formed by the casting method. Furthermore, the samples that had been formed in sheet form were dried at room temperature for 2 hours. The sample characterization includes measurement of density, tensile strength test, and magnetic field strength using a Gauss meter. Based on the characterization results, with the increase in the SR composition the density value tended to decrease, but the tensile strength and elongation values tended to increase up to the composition of 20% SR, then decreased at the composition of 30% SR. This means that the more SR content, the flexibility tends to increase. Based on the measurement of magnetic strength using a Gauss meter, it shows that samples with an increasing SR composition, the value of the magnetic field strength tends to decrease.

Medical robots have massive potential for improving the precision and capabilities for doctors to perform surgical procedures. For detecting colon cancers, these robots are also capable of suturing and inchworm devices can move over the narrow passages as required inside human colon. Most of the existing medical robots are designed and developed in order to enhance their stiffness to minimize the vibration of the end-effectors to obtain good position accuracy. In addition to this, it is important to study the dynamic characteristics of the colonoscope, such as load, stress, and strain for understanding the suitability of material used for colonoscope. In this paper, silicone rubber with selected specifications is used as colonoscope material and Mooney Rivlin equations are solved using ABAQUS software. Pneumatic pressure is taken as input parameter (0.1 MPa to 0.5 MPa). Finite Element Simulation is carried out and results are plotted for various set of values of input pressure. The results obtained indicate that silicone rubber with specified characteristics is a suitable material for colonoscope and it increases the comfort for the patient by exerting less force on the colon while it is moved inside the colon. [ABSTRACT FROM AUTHOR]

Co0.5Zn0.5Fe2O4 ferrite nanoparticles were prepared using sol–gel citrate method. (Silicone Rubber/CoZn nanoferrite) composite samples with ferrite loadings (5, 8, 11, 14 and 17) phr were synthesized. XRD, TEM and FTIR techniques were used to investigate the structure and morphology of ferrite while SEM and FTIR techniques were utilized to study the structure of the rubber/nanoferrite composites. The effect of frequency (50 Hz to 5 MHz), nanoferrite load and temperature (30 to 195 °C) on the real and imaginary parts of the electric permittivity (ε′ and ε′′) showed an increase up to ferrite load up to 8 phr sample. Results were explained in the light of Debye theory of dielectrics using some models based on Clausius–Mossotti equation. The mechanical parameters (tensile strength, elongation at break and Young's modulus) were enhanced up to ferrite load (8 phr) which reflects the improvement of the performance of these composite samples. [ABSTRACT FROM AUTHOR]

A simple method for the preparation of multifunctional nanocomposite was developed towards the production of water‐repellent, electrically conductive, and photoluminescent film onto cotton fibres. The nanocomposite was composed of lanthanide‐doped strontium aluminium oxide and silicon rubber dispersed in petroleum ether. The electrically conductive fabric was woven from nickel strips twisted with cotton filaments as core yarns, which were wrapped with pure cotton yarns. The nanoparticles (NPs) of lanthanide‐doped strontium aluminium oxide were mixed with environmentally friendly room‐temperature vulcanizing silicon rubber (RTV‐SR) dissolved in petroleum ether to give the silicon rubber/strontium aluminate nanocomposites. The produced nanocomposites were applied onto electrically conductive cotton/nickel fibres using spray‐coating technology. The surface of the cotton/nickel fibres showed different hierarchical morphologies depending on the total content of the silicon rubber. Additionally, the superhydrophobic effect was found to be improved upon increasing the total content of the luminescence pigment NPs. The morphologies of the prepared phosphor NPs were determined using transmission electron microscopy (TEM). The generated transparent luminescence film demonstrated an absorbance peak at 358 nm and an emission peak at 515 nm. Photoluminescence of cotton fibres was monitored with the generation of different colours, including grey, green‐yellow, bright white, and turquoise shades as recognized using CIE Laboratory colorimetric parameters. The emission, excitation, lifetime, and decay time spectra of the phosphorescent spray‐coated cotton samples were studied. The surface morphologies and chemical compositions of the spray‐coated cotton/nickel were investigated using wavelength‐dispersive X‐ray fluorescence (WD‐XRF), scanning electron microscope (SEM), Fourier‐transform infrared spectra (FTIR), and energy‐dispersive X‐ray analyzer (EDAX). The superhydrophobic effects were characterized by measuring static water contact angle. The comfort characteristics of the treated cotton/nickel substrates were assessed by investigating their air permeability and stiffness. The treated cotton/nickel fabrics also displayed an antimicrobial activity. The results displayed water repellence with high electrical conductivity and photoluminescence properties. [ABSTRACT FROM AUTHOR]

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.

Objective The present study investigated the clinical effects of a single complete denture using two ⁃ step fine impression during the restoration of mandibular alveolar ridge atrophy. Methods A back ⁃end window tray that was personalized and adjusted was used to obtain the original impression for a mandibular alveolar ridge case. The individual trays were made with the conception of mandibular occlusal denture, and the final impression was obtained after active edge shaping using different viscous silicones. Results A case of single complete denture with mandibular alveolar ridge atrophy restoration was accomplished using a single complete denture and two⁃step fine impression. The denture was well fixed and functioned well, and the patient was satisfied. Conclusion The application of fine impres⁃ sion into a single complete denture is helpful for the restoration of mandibular alveolar ridge atrophy.

When rubber is subjected to a load, deformation will occur in the form of transverse compression. At a microscopic level, the bond structure in the rubber is transformed from one equilibrium state, corresponding to the unloaded rubber, to another, corresponding to the loaded rubber. As in any transformation process, this takes a certain amount of time called transient response time. This paper presents a simple fibre sensor configuration to experimentally monitor transient response of the loaded rubber bar at a desired point in the rubber at a constant temperature is presented. For this purpose, a coil of polymer optical fibre (POF) with cross-section diameter 10 mm was inserted into a cylindrical rubber rod with cross-section diameter of 3 mm and thickness of 2 cm. Five different loads (2 kg, 2.5 kg, 3 kg, 4 kg and 7 kg) were carefully placed on the cylindrical rubber rod and the resulted change in transmitted light intensity through the fibre sensor was recorded. It was shown that transient response time is load mass dependent which increases with increasing load. Transient response time was also measured as function of depth, it decreases with the increase of the depth, i.e., vertical distance from rubber rod surface. In addition to static loading, transmission curve resulted from dynamic loading was also demonstrated. Based on these results we suggest that smart rubber might be simply formed by sandwiching optical fibre coil into one or more desired points in the rubber bar. [ABSTRACT FROM AUTHOR]

The aim of this article is to improve the interfacial adhesion between silicone rubber (SR) and Rayon fiber by the help of functional hybrid POSS nanoparticles. Two POSS types were compared, octavinyl‐POSS (O‐POSS) and methacryl‐POSS (M‐POSS), having reactive CC double bonds that can impart in peroxide crosslinking. O‐POSS is nonpolar, whereas M‐POSS is polar and is able to make H‐bond with Rayon fibers. POSS type and their concentrations were examined as the experimental parameters. H‐adhesion tests indicated that both POSS types enhanced the adhesion of SR composites to Rayon fibers compared with control recipe. Specifically, slightly higher values were obtained with the use of M‐POSS. It was observed that both O‐POSS and M‐POSS slowed down the curing rate but increased the degree of crosslinking. The cure extent of O‐POSS containing composites was found to be higher than that of M‐POSS containing ones. Thermal gravimetric analyses revealed that thermal stability of SR composites was significantly improved by the addition of POSS particles. Higher char yield and degradation temperatures were obtained with O‐POSS at higher loadings with respect to M‐POSS. The POSS distribution at lower loading levels was found to be homogenous for both POSS types as observed from scanning electron microscope and transmission electron microscope. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a new pneumatic actuation method inspired from a soft robot, which could drive the multi-stable carbon fiber-reinforced polymer (CFRP) structure transition among five stable configurations under air pressure. Multi-stable structure was manufactured by the carbon fiber prepreg laid in asymmetrical and anti-symmetric layup methods and stacked at the joint during the preparation process according to the designed scheme. In experiments, multi-stable structures with two different fibers layups were prepared to study the snap-through behaviors. The snap-through process of two kinds of multi-stable structures was investigated by experiment. The parameters used to characterize efficiency of the pneumatic actuator actuating the multi-stable structures, including air pressure and snap time, were measured. The influence of the pneumatic actuator on the curvature of multi-stable structures was discussed by comparing the shape characteristic of multi-stable structures with or without pneumatic actuation, and it showed pneumatic actuator has little effect to the structure. The results demonstrated that the proposed pneumatic actuation could be used to drive multi-stable morphing structure flexibly. The combination of multi-stable laminates develops the function of multiple point bending and shape retention of pneumatic actuation. [ABSTRACT FROM AUTHOR]

Robust superhydrophobic surfaces with periodic array structures composed of circular silica islands on silicone rubber substrates were fabricated using a combination of multi-laser exposure and chemical modification. Abrasion tests with sandpaper demonstrate that hard silica regions on the surface can protect the silicone rubber region from external damage, resulting in long-lasting superhydrophobicity. Moreover, with an increase in area fraction and a decrease in array hole radius, the wear of the filled superhydrophobic silica is slowed while the protection for the silicone rubber region is enhanced. Particularly, the optimum surface geometry had an area fraction of 35 % and array hole radius of 100 μm retaining its hydrophobicity up to 63 times of abrasion, eight times more than that of the superhydrophobic surface processed by lasers alone. The results of a sand impact test confirmed the resulting surface's resilience in an aeolian sand environment. This research demonstrated the feasibility of producing robust, superhydrophobic surfaces on flexible silicone rubber substrates and providing a foundation for improving and innovating related products. [Display omitted] • Superhydrophobic silicone rubber surface was fabricated by laser processing and silica filling. • The periodic array structures provide surface protection and maintain flexibility. • Circular silica islands in surface periodic array structures exhibit a self-similar property. • Rubost surfaces demonstrate long-lasting superhydrophobicity during abrasion. [ABSTRACT FROM AUTHOR]

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.

Benzoxazine resin is a new generation of anti-ablation resin with high char yield and high-temperature oxidation resistance. Using high temperature vulcanized silicon rubber as ablation resistance matrix and 2,2'-(3-methyl-4-dihydro-1,3,2-benzoxazine)propane as anti-ablation resin, silicon rubber/polybenzoxazine anti-ablation composite was prepared by blending method. The mechanical properties were tested,and the ablation structure and the composition of the composite were investigated by DSC,SEM,FT-IR and Raman.Experimental results show that the polybenzoxazine resin can improve the ablation resistance property of silicone rubber composite. The composite has good ablation resistance and mechanical property when the addition of polybenzoxazine resin reaches 20 phr. After ablated by oxygen acetylene flame,the ablation layer is divided into three obvious layers as surface ceramic layer,pyrolysis carbonization layer and base layer. The surface ceramic layer formed in the progress of ablation plays a positive role in the ablation property of the composite material.