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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]

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]

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]

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]

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]

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]

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]

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]

• Flame retardancy of VMQ was improved by the synergistic effect of HPCP and APP. • The best flame-retarded VMQ got LOI value of 30.6% and UL-94V-0 rating. • The flame retardancy index of HPCP and APP at mass ratio of 1:1 was excellent. • Flame retarding mechanisms in the gaseous and condensed phase were both discussed. In order to improve the flame retardancy of methyl ethyl silicone rubber (VMQ), the synergistic effect of an intumescent flame retardant (IFR) system consisting of hexophenoxy cyclotriphosphazene (HPCP) and ammonium polyphosphate (APP) was investigated. The results showed that with a total loading of 30 wt% IFR, the flame-retarded VMQ composite got the highest limiting oxygen index (LOI) of 30.6% and UL-94V-0 rating at mass ratio of HPCP and APP of 1:1. Meanwhile, the flame retardancy index (14.88) indicated that the synergistic effect of the system was excellent. Then digital photographs, SEM images and FTIR spectra of residue chars obtained from the CC test demonstrated the flame retarding mechanism in the condensed phase. In addition, mechanisms were also discussed based on TG and Py-GCMS results. [ABSTRACT FROM AUTHOR]

A kind of paraffin@graphene/silicone rubber (SR) composite form-stable phase change material (PCM) was prepared in this paper. Paraffin@graphene phase change microcapsules were fabricated by electrostatic self-assembly method, then the microcapsules were added to the SR matrix to prepare paraffin@graphene/SR composites. The microstructure of the composite was characterized by scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) and thermal conductivity test results show that the phase change latent heat is 53.39 J g−1 and the thermal conductivity reaches 0.453 W m−1 K−1 for the composite with 30 phr paraffin@graphene microcapsules. The microcapsules enhance the thermal and mechanical properties of SR, which can be used for thermal energy storage. [ABSTRACT FROM AUTHOR]

The visualization analysis of dispersion state of the filler m silicone rubber was based on the fluorescent labeling and the laser scanning confocal microscope. The fluorescent silica microspheres were modified by different silane coupling agents, and the contact angle analysis, thermogravimetnc analysis and fluorescence spectroscopy were used to describe its surface properties. Both hydrophobic effect and bound rubber content of modified fluorescent silica microspheres are KH-570>KH-560>KH-550. Visual analysis results show that the aver- age size of aggregates and network connectivity of KH-570 modified fluorescent silica microspheres were 2.61 ̡m and 47%, KH-560 modified it were 2.95 /im and 43% and KH-550 modified it were 3.32 f(m and 41 %. The visual analysis method of the modified fluorescent SiO2 microsphere is beneficial to observe the dispersion state of it m the silicone rubber, and this method can statistically analyze the particle size of the modified fluorescent SiO2 microsphere aggregates. This method is helpful to evaluate the dispersion state of the filler m the silicone rubber. [ABSTRACT FROM AUTHOR]

To study how the flashover voltage of silicone rubber depends on surface roughness, we prepared samples of silicone rubber of varying surface roughness to explore the relationship between surface roughness and the hydrophobicity of silicone rubber. We investigate the surface-flashover voltage of these samples. The results show that an increase in surface roughness leads to a decrease in the hydrophobicity of silicone rubber. The-dry flashover voltage of a sample with high surface roughness increases with surface roughness, and the wet-flashover voltage is reversed. The flashover characteristics for a attached water droplet depend mainly on the length of the water droplet. • The relationship between surface roughness and the hydrophobicity of silicone rubber was explained. The test results show that the hydrophobicity of silicone rubber decreases with increasing surface roughness. The spray-grading method and the contact-angle method produce different results for the degree of hydrophobicity. • The relationship between the flashover voltage and the hydrophobicity of silicone rubber was explained. The wet-flashover voltage decreases with the increase of roughness. Numerical simulations show that the degree of distortion of the surface electric field increases with surface roughness. • By comparing simulation results with experimental results, it is considered that the dry-flashover characteristics of rough silicone rubber surface in air are determined by the creeping distance of the surface and the degree of electric field distortion. [ABSTRACT FROM AUTHOR]

[Display omitted] • The mechanical properties of composites at low temperature were studied. • The effect of the ratio of ZnO to LDH on the properties of rubber was studied. • Composite fillers improve the tensile properties of rubber. • Composite filler reduces glass transition temperature of rubber. • Construction of cross-linked network of ZnO and LDH in rubber. Low-temperature conditions can degrade various properties of rubber, impacting the application of rubber products in such conditions. In this study, we incorporated zinc oxide (ZnO) and magnesium aluminum layered double hydroxide (LDH) into silicone rubber (SR) to produce x-ZnO/LDH/SR composites, where X represents the addition ratio of ZnO to LDH. The results indicated that, at −40 °C, the tensile strength and elongation at break for 1/2-ZnO/LDH/SR were 10.6 % and 5.0 % greater than the original silicone rubber, respectively. In addition, after aging at −40 °C for 3 days, the compression set of the composites decreased by 48.6 %. This improvement was attribute to ZnO and LDH forming a physical cross-linking network within the rubber. This not only enhanced the mechanical properties of silicone rubber at low temperatures but also offers a straightforward and viable approached to producing high-performance, low-temperature-resistant sealing products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cyclosiloxane with single C=C bond was synthesized by hydrocondensation and was further copolymerized with octamethyl cyclotetrasiloxane to prepare silicone rubber with well-distributed crosslinking groups. • The effect of vulcanization groups type on vulcanization rate was investigated. • The well distribution vulcanization groups enhanced the mechanical properties of SR. • The matched vulcanization rate of SR with EPDM improved the mechanical properties and breakdown strength of SR/EPDM blends. Due to the low intermolecular force, silicone rubber (SR) processes weak mechanical properties and it's difficult to blend with other conventional rubbers, which limits its application. Herein, a series of novel SRs with evenly distributed and different types of crosslinking groups were synthesized and cured to SR blends. The novel SRs promote the uniform distribution of crosslinking points during vulcanization, which contributes to the increase in both tensile strength and elongation at break. Besides, the introduction of different types of crosslinking groups decreases vulcanization speed as well as increases the flexibility of the bridge between two crosslinked polymer chains, resulting in the elongation at break as high as 1143%, which is twice higher than commercial SR. The novel SRs were subsequently blended with ethylene-propylene-diene rubber (EPDM) to prepare high-performance blends. Compared with the commercial SR/EPDM blend, the matching vulcanization resulted in an increase in the tensile stress and elongation at break by 27.6% and 35.3%, respectively. In addition, dielectric strength increases from 34.2 to 40.8 kV/mm for SEP-VCH. Our work provides a new strategy to prepare SR with high mechanical properties and improve the properties of SR/EPDM blend without the addition of a compatibilizer, thus extending the application of SR. [ABSTRACT FROM AUTHOR]

Shock wave properties of porous specimens made on the basis of matrices composed of inert and chemically active media (silicon rubber and emulsion, which is an aqueous solution of ammonium nitrate with mineral oil and emulsifier) are studied. The porosity of the specimens is generated by using a filler composed of glass microspheres. The wave velocity profiles are measured by a VISAR laser Doppler interferometer. It is shown that the shock compressibility of porous silicon rubber at pressures below 0.1 GPa displays an anomalous behavior, resulting in smearing of the compression pulse front propagating over the specimen. In the emulsion matrices without microspheres, there are no noticeable chemical transformations up to the pressure of 15 GPa. Addition of microspheres drastically decreases the threshold of chemical reaction initiation and leads to the formation of a steady detonation wave. [ABSTRACT FROM AUTHOR]

To clarify the relationship between microporous defects and the development of partial discharge(PD) in silicone rubber, meanwhile evaluate insulation state of the prefabricated power cable joints quantitatively, the microporous defect is made based on real power cable joint, and PD signals are measured by step test method with the development of the defect. The discharge number, total energy and average energy of PD is gained to calculate the curves changed over time, based on which the breakdown process is divided into 4 stages, then phased spectra and grayscale maps are calculated for reflection of PD repetition rate and average energy in phase domain. Phase width, skewness of spectrum and coefficient of variation of parameter are employed to indicate the spectra statistical shape feature in each stage. The study indicates that the shape features of spectra are changed during the development of defect, the 3 features parameters are monotonously changed, and the changing rate is significantly higher at the end of the breakdown process. Evaluation method for micropores PD of silicon rubber is proposed based on the analysis of the parameters and the trend of PD's development. [ABSTRACT FROM AUTHOR]

This work combines experiments and finite element simulations to study the effect of pre-imposed cyclic loading on surface instability of silicon rubber under compression. We first fabricate cuboid blocks of silicon rubber and pinch them cyclicly a few times. Then, an in-house apparatus is set to apply uniaxial compression on the silicon rubber under exact plane strain conditions. Surprisingly, we find multiple creases on the surface of silicone rubber, significantly different from what have been observed on the samples without the cyclic pinching. To reveal the underlying physics for these experimentally observed multiple creases, we perform detailed nanoindentation experiments to measure the material properties at different locations of the silicon rubber. The modulus is found to be nonuniform and varies along the thickness direction after the cyclic pinching. According to these experimental results, three-layer and multilayer finite element models are built with different materials properties informed by experiments. The three-layer finite element model can excellently explain the nucleation and pattern of multiple surface creases on the surface of compressed silicone rubber, in good agreement with experiments. Counterintuitively, the multilayer model with gradient modulus cannot be used to explain the multiple creases observed in our experiments. According to these simulations, the experimentally observed multiple creases should be attributed to a thin and stiff layer formed on the surface of silicon rubber after the pre-imposed cyclic loading. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hexagonal boron nitride (h-BN) nano sheets were prepared from nanoparticles by a novel/effective exfoliating agent (i.e. mono ethylene glycol). • Exfoliation of h-BN was performed much better in mono ethylene glycol as replacing solvent for water/isopropyl alcohol. • Silicon rubber (SR) nanocomposites were prepared using pure and exfoliated h-BNs and evaluated for thermal and electrical properties. • The exfoliated h-BNs caused considerable improvement in the thermal conductivity and electrical resistance of SR compared to pure h-BNs. 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. [ABSTRACT FROM AUTHOR]

Shielding material is used for protection against harmful effect of ionizing radiations. This paper is aimed at studying the prospects of silicone elastomer based nanocomposites as neutron shielding material. Cadmium oxide (CdO) nanoparticles and multi-walled carbon nanotubes (MWCNTs) were used as filler medium in the nanocomposites, due to their exceptional neutron attenuation properties. The CdO nanoparticles were synthesized using composite-hydroxide-mediated (CHM) method and their structural purity was confirmed with x-ray diffraction data. Silicone/CdO/MWCNTs nanocomposites were fabricated by room-temperature-vulcanization (RTV) method, with different concentrations of nano-fillers (3, 6 and 9 % wt of CdO; 1 % wt of MWCNTs). The half value layer (HVL) thickness of the nanocomposites were found to be 7.44 cm, 5.90 cm and 5.72 cm, while the neutron removal cross sections were noted as 0.09307, 0.11732, and 0.12107 for the nanocomposites containing 3%, 6% and 9% of CdO, respectively. The Phy-X software was used to calculate the fast neutron removal cross-section and found it consistent with the experimental results. The results revealed that adding nano-fillers (CdO nanoparticles and MWCNTs) into silicone matrix not only enhanced the neutron shielding efficacy of nanocomposites but also have improved their mechanical properties and making it useful for neutron shielding applications. • Neutron shielding efficacy of silicon rubber composited was investigated. • Effect of CdO contents on mass removal cross section was explored. • HVL values of silicon composites with CdO and MWCNTs were figured out. • Experimental results were confirmed by simulation with Phy-X/PSD software. [ABSTRACT FROM AUTHOR]

cis- and trans-Isomers of the platinum(II) nitrile complexes [PtCl2(NCR)2] (R = NMe2, N(C5H10), Ph, CH2Ph) were examined as catalysts for hydrosilylation cross-linking of vinyl-terminated polydimethylsiloxane and trimethylsilyl-terminated poly(dimethylsiloxane-co-ethylhydrosiloxane) producing high quality silicone rubbers. Among the tested platinum species the cis-complexes are much more active catalysts than their trans-congeners and for all studied platinum complexes cis-[PtCl2(NCCH2Ph)2] exhibits the best catalytic activity (room temperature, c = 1.0 × 10–4 mol/L, τpot-life 60 min, τcuring 6 h). Although cis-[PtCl2(NCCH2Ph)2] is less active than the widely used Karstedt’s catalyst, its application for the cross-linking can be performed not only at room temperature (c = 1.0 × 10–4 mol/L), but also, more efficiently, at 80 °C (c = 1.0 × 10–4–1.0 × 10–5 mol/L) and it prevents adherence of the formed silicone rubbers to equipment. The usage of the cis- and trans-[PtCl2(NCR)2] complexes as the hydrosilylation catalysts do not require any inhibitors and, moreover, the complexes and their mixtures with vinyl- and trimethylsilyl terminated polysiloxanes are shelf-stable in air. Tested catalysts do not form colloid platinum particles after the cross-linking. [ABSTRACT FROM AUTHOR]

Finite element method simulations were implemented to understand how the strain energy is distributed in a disk-like sample during a punch shear test. Material's Young modulus can be estimated from this test; however, there is not enough available information about the distribution of the strain energy inside the sample during the deformation process. The proposed methodology seeks to give insight into the deformation process. Experimental results for a cured silicon rubber sample were used to validate the simulation results. It was found that the estimation of the Young modulus with the punch shear test depends on the ratio between the span-to-punch diameters. This conclusion applies to the simulated results, following Timoshenko's theory for the deformation of thin plates. Understanding how energy is accumulated during a punch shear test is an important and useful characteristic in terms of the design of armor systems. [ABSTRACT FROM AUTHOR]

An innovative bioinspired method is presented for the preparation of surface-modified nanodiamonds (ND) particles by poly(dopamine) (PDA). The process was aimed at improving the thermal conductivity and maintaining the insulating capability of silicone rubber (SiR). ND was successfully and effectively modified by dopamine in different hours, which was confirmed by HR-TEM, TGA, FTIR, and XRD. The poly(dopamine) coating on ND particles improved its interfacial interaction with silicon rubber and promoted the uniform dispersion of fillers, resulting in the ND-18/SiR composite that acquired a higher thermal conductivity (0.295 W/(m·K)) at the loading of 6 wt%, 81 % higher than that of pure silicone rubber (0.163 W/(m·K)). In addition, the composite materials still displayed an excellent insulating property with a resistance of ≈1011 Ω·cm, which was a big advantage for thermal management. [Display omitted] • The agglomeration problem of ND nanoparticles was reduced by using dopamine. • ND-X particles exhibit excellent dispersibility and compatibility with SiR. • ND-X particles enhance thermal conductivity and maintain electrical insulation of nanocomposites. [ABSTRACT FROM AUTHOR]

The surface pressure-sensitive characteristics of carbon black/silicon rubber (CB/SR) composites with positive pressure coefficient of impedance (PPCI) effect were researched. The linearity is very good when the impedance’s logarithm changes with the applied load at optimal operating frequency (1 KHz). The pressure sensor based on the flexible composites exhibit fast response when pressures are applied and canceled with a response time of 3 s. The sensor appears a higher sensitivity in AC electrical field than that in DC electrical field. Dielectric polarization theory was used to explain the sensitive behavior of the pressure sensor. Internal structure diagrams of CB/SR composites were used to explain the positive pressure coefficient of resistive (PPCR) effect and negative pressure coefficient of capacitive (NPCC) effect. AC electric field is applicable for the flexible pressure sensor based on conductive silicon rubber composites. [ABSTRACT FROM AUTHOR]

Printed electronics, in which microcircuit patterns are fabricated using printing methods, are the focus of considerable attention for the fabrication of devices such as flat panel displays, solar cells, and flexible electronics. In particular, gravure offset printing is considered to be a highly promising approach for rapid printing of fine patterns with well-controlled thickness. At present, however, because of the occurrence of side etching during fabrication of metal printing plates, features with dimensions of less than 10 µm cannot be printed. In order to overcome this problem, we have previously proposed the use of a rubber printing plate fabricated by photolithography and molding, which is free from side-etching issues. However, deformation of the printing plate can have a detrimental influence on the transferred pattern. In the present study, we developed a method for visualizing the deformation of a printing plate containing both micropatterns and nanopatterns, in order to study its effect on the printing process. The results were compared with those predicted by an analytic equation under a uniform controlled pressure. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Printed electronics, in which microcircuit patterns are fabricated using printing methods, are the focus of considerable attention for the fabrication of devices such as flat panel displays, solar cells, and flexible electronics. In particular, gravure offset printing is considered to be a highly promising approach for rapid printing of fine patterns with well-controlled thickness. At present, however, because of the occurrence of side etching during fabrication of metal printing plates, features with dimensions of less than 10 μm cannot be printed. In order to overcome this problem, we have previously proposed the use of a rubber printing plate fabricated by photolithography and molding, which is free from side-etching issues. However, deformation of the printing plate can have a detrimental influence on the transferred pattern. In the present study, we developed a method for visualizing the deformation of a printing plate containing both micropatterns and nanopatterns, in order to study its effect on the printing process. The results were compared with those predicted by an analytic equation under a uniform controlled pressure. [ABSTRACT FROM AUTHOR]

• Phosphazene derivative served as cross-linking agents of silicone rubber. • The mechanical strength and thermal properties were significantly improved. • Characterization of the char layer structure and surface elements composition. • Analysis of ceramicization reaction and ablation mechanism. It is still a challenge for liquid silicone rubber to meet the needs of aerospace and electronics in terms of mechanical and thermal properties. In this study, N 3 P 3 [NH(CH 2) 3 Si(OCH 2 CH 3) 3 ] 6 (APESP), a phosphazene derivative containing multiple siliconethoxy groups was adopted as cross-linking agent to cure the condensed room temperature vulcanizing liquid silicone rubber (RTV-CLSR). The results show that APESP can effectively complete the curing process of condensed silicone rubber taking the place of tetraethyl orthosilicate (TEOS), and enhance the restriction of cross-linking point to molecular chains, thereby effectively improving the mechanical strength, thermal stability, and ablation resistance of SR. Compared with unmodified SR, the tensile strength of APESP modified SR increased by 272%, the elongation at break decreased slightly but still remained at 362%, and the mass residual rate at 800 °C significantly increased by 19.86% when 11 phr APESP was added. The linear ablation rate and mass ablation rate of SR were reduced to 0.239 mm·s−1 and 0.095 g·s−1, a decrease of 60.63% and 44.41%, respectively. This work may provide a new perspective for the application of liquid silicone rubber in the fields with high thermal performance requirements. [ABSTRACT FROM AUTHOR]

In this work, the dissolution and diffusion behaviors of different supercritical fluids (SCFs) including CO 2 , N 2 and their mixtures in silicon rubber were investigated by magnetic suspension balance (MSB) and a situ visualization system to trace the expansion of sample's volume. The results showed that the mixed gas in silicon rubber having an appropriate proportion could maintain the high solubility while obtaining relatively low diffusion coefficient. In addition, a processing strategy which utilized conjunctively the CO 2 with high solubility and N 2 with low diffusivity in silicon rubber was used to design the cellular structure and improve shrinking problem. The resulting silicon rubber foamed by mixed gas has a lowest density of 0.086 g·cm−3 and the problem of cell shrinking has been improved effectively. This approach widens silicon rubber's potential as a high-performance foam material and provides an idea for preparing ultra-light silicone rubber foam material. [Display omitted] • The solubility and diffusion behaviors of different supercritical fluids in silicon rubber were investigated in this paper. • A situ visualization system was attached to magnetic suspension balance (MSB) to trace the expansion of sample's volume. • The cellular structure of silicon rubber was designed by foaming agents with different solubility and diffusion coefficients. • A mixture of CO 2 and N 2 was used to prepare silicon rubber foam which could improve effectively cell shrinkage. [ABSTRACT FROM AUTHOR]

High permittivity and large actuation strain under low actuation voltage have been the "hotspot" on the development and application of dielectric elastomer actuators (DEAs) for decades. In this work, by coating multi-walled carbon nanotube (MWCNT)/silicon rubber (SR) composite on the surface of nickel foam, after which the nickel foam was etched, the segregated MWCNT network structure was filled and encapsulated by SR. As a result, an isolated three-dimensional (3D) MWCNT network was successfully introduced into the SR elastomer matrix. Studies showed that owing to the large amount of accumulated charge on the large polarization interface between MWCNT and SR, high dielectric constant value as high as 10.39 at 1 kHz under 0.8 wt % MWCNT can be endowed to the composited elastomer. In addition, because discontinuity of adjacent MWCNTs in the 3D MWCNT network, the dielectric loss and elastic modulus of the composited elastomer has been significantly lowered, providing a high actuated strain of about 11.61% at a low electric field of 10.1 V·μm−1 under a filler content of 0.6 wt % to the composites. This finding raises a long-range prospect to readily and reliably prepare high-performance polymer based dielectric materials, and the 3D-MWCNT/SR composite elastomer seizes a great potential to be applicated as high-performance DEAs. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The main cause of degradation and breakdown in silicon rubber (SIR) is electrical treeing. Based on a series of experiments, this paper discusses the morphology of the electrical trees. The types of morphology of electrical trees in SIR are concluded. The effective factors of the tree initial type are explored. And the propagation characteristics are also studied through long-term electrical tree ageing experiments. These results are also compared with the electrical trees occurred in on-site cable accessories and those in PE which are more familiar to researchers. Based on those experiment results, an explanatory mechanism is proposed. [Copyright &y& Elsevier]

Porous asymmetric polyethersulfone (PES) hollow fiber membrane was fabricated via dry/wet spinning process. The spinning dope consisted of 18 wt.% PES in N-methyl-2-pyrrolidone (NMP) solvent. Distilled water was used as bore fluid to make hollow fiber membrane without inner skin layers. Then, a skin layer consisting of poly (4-vinyl pyridine), PVP, silicon rubber PDMS and silica nanoparticles (nano-SiO) was transferred to the PES substrate surface by means of a dip coating method, leading to a nanocomposite hollow fiber membrane. Investigation of the cross-section of the prepared membranes via scanning electronic microscopy (SEM) revealed a good adhesion between the top dense layer and the PES substrate. Moreover, tensile strength and ultimate elongation of the pristine membrane were increased 2.3 and 5 times, respectively, when the PVP/PDMS/nano-SiO coating was formed on its outer surface. Finally, according to the results of gas permeation tests, the prepared nanocomposite membrane, with a CO/CH selectivity of 45 and CO permeance of 102 GPU would be an attractive candidate for applications such as natural gas purification and control of anthropogenic carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

Polymeric insulators have gained popularity since the last 30 years throughout the world. The main concern about them is variation in their performance with varying environments. Investigation of their performance by natural and artificial aging experiments is under the way by many researchers all over the world. The natural aging is usually short-term experiment ranging from few days to few years. The artificial aging is usually long-term investigation in lab that simulates the real service environment. However, first of all to develop the artificial aging schemes, natural aging to some extent is necessary. This article presents a part of research on polymeric insulators ongoing at the University of Engineering & Technology, Taxila, in which 2 different kinds of polymeric insulators were naturally aged in a period of 1 year. The materials used were the thermoplastic elastomeric and thermoset silicone rubber (SiR) insulators. They were aged in outdoor environment of Hattar, which is a heavily polluted industrial area of Pakistan. The actual 11 kV full-scale insulators were installed in open environment at a height of about 30 m. The samples were cut from the insulators and analyzed using visual observation, hydrophobicity classification, leakage current and Fourier transform infrared spectroscopy and scanning electron microscopy. The main aims of this aging were estimation of the useful life of these insulators under the environment studied and development of basis for multistress lab aging cycles. The results were also used to compare the performance of these two materials with each other. [ABSTRACT FROM PUBLISHER]

The thermal properties of PA66/PC/silicone rubber composites prepared by dynamic vulcanization were investigated. By adding silicone rubber as a toughener, engineering plastics with outstanding thermal properties were prepared via reactive extrusion. The PA66/PC/silicone rubber composites show very good retention of impact strength and higher hardness even after heat aging. The average degradation and softening temperatures of the composites are higher than that of other common engineering plastics that we mainly attribute to the introduction of the dynamically vulcanized silicone rubber and the forming of a net-like structure in the PA66/PC matrix. The addition of montmorillonite improved the hardness and the degradation temperature of the composites. [ABSTRACT FROM AUTHOR]

Abstract: Based on the characteristic that silicon coupling agents have the capability to develop ‘molecular bridge’ in the interface of organic materials and inorganic materials, silica films were prepared on the surface of flexible silicon rubber by sol–gel method and the optical transmittance of the sample before and after atomic oxygen irradiation was tested. The surface morphology and structure of silica films were investigated by scanning electronic microscope (SEM) and Fourier transformed infrared spectroscopy (FTIR). The results indicated that the silica sol could easily form a uniform thin film on the surface of silicon rubber pretreated by high concentration silicon coupling agents, and the inorganic silica films could combine with organic silicon rubber without obvious delamination on the interface. [Copyright &y& Elsevier]

A new methodology was developed to observe and measure tool wear and tool surface quality during the die compaction process. The newly developed method is a non-destructive test that relies on silicon rubber to transcribe the inner surface profile of the compaction die. After verification of the method, aluminium and iron alloy powders were compacted to quantify tool wear and tool surface quality with two die materials, tungsten carbide and tool steel. The tool surface quality was quantified by recording surface roughness of the die replicas on a surface profilometer. [ABSTRACT FROM AUTHOR]

In this study, synthetic silicone rubber (SR) and Bi2O3 micro- and nanoparticles were purchased. The percentages for both sizes of Bi2O3 were 10, 20 and 30 wt% as fillers. The morphological, mechanical and shielding properties were determined for all the prepared samples. The Linear Attenuation Coefficient (LAC) values of the silicon rubber (SR) without Bi2O3 and with 5, 10, 30 and 30% Bi2O3 (in micro and nano sizes) were experimentally measured using different radioactive point sources in the energy range varying from 0.06 to 1.333 MeV. Additionally, we theoretically calculated the LAC for SR with micro-Bi2O3 using XCOM software. A good agreement was noticed between the two methods. The NaI (Tl) scintillation detector and four radioactive point sources (Am-241, Ba-133, Cs-137 and Co-60) were used in the measurements. Other shielding parameters were calculated for the prepared samples, such as the Half Value Layer (HVL), Mean Free Path (MFP) and Radiation Protection Efficiency (RPE), all of which proved that adding nano-Bi2O3 ratios of SR produces higher shielding efficiency than its micro counterpart. [ABSTRACT FROM AUTHOR]

Abstract: Some novel composites were prepared with polypropylene and silicon rubber with wollastonite as fibrous filler having aspect ratio 5:1 in different proportions. Subsequently, these composites were investigated for tensile, impact (notched and unnotched), flexural strength, flexural modulus and heat deflection temperature (HDT). A special interest has been devoted to the measurement of flexural modulus and heat deflection temperature since this is an important property in many applications. The results show that there is a marginal change in mechanical properties of the untreated wollastonite-filled polypropylene composite on addition of silicon rubber and malicanhydride, whereas the enhancement in the HDT was significant. In specific, an addition of 5% rubber in the polypropylene composites having wollastonite at different compositions of 10%, 20%, 30% and 40% provided, in general, enhanced HDT, notched impact strength and flexural strength, but, reduced unnotched impact strength, tensile strength and flexural modulus. [Copyright &y& Elsevier]

Abstract: Silicon rubber, PDMS, was irradiated by Ar, Ar/H2 and Ar/O2 plasmas to increase the surface wettability to water which was found to increase with the irradiation time for every application of plasma irradiation. The use of Ar/O2 plasma was found to be particularly effective in enhancing the surface wettability. The aging behavior due to exposure to air, ethanol or water was also measured. In the case of continuous exposure to water after plasma treatment, the wettability could be maintained for more than several months with the water immersion. [Copyright &y& Elsevier]

Abstract: Silicon rubber (SR) based thin film composite (TFC) membranes find increasing applicability in various industrial separations owing to its excellent thermal and chemical stability. The functionalization of SR would provide enhanced separation characteristics for certain separation applications. The present research focuses on gas permeation properties of dense and thin film composite membranes based on amine substituted silicon rubber (ASR) and unsubstituted silicon rubber (SR). The dense membrane sorption analysis indicated that presence of amine functionality in ASR increased pressure dependant CO2 sorption capacity. Owing to this, an elevation of CO2 permeability by 15% and CO2 based selectivities by 22–34% in comparison to that of unsubstituted SR was observed. The TFC membranes with SR and ASR as the selective layer on the top of different ultrafiltration (UF) supports with varying properties based on polyacrylonitrile and polysulfone were prepared. The effects of crucial parameters that affected TFC membrane performance, viz., coating solution concentration, UF support membrane porosity and nature of materials were investigated. The preparation of ASR based TFC membranes was demonstrated with a simple crosslinking agent—glutaraldehyde while analyzing effects of crosslinking time on their permeation properties. Polyacrylonitrile (PAN) was found to be better support layer material for ASR based TFC formation than polysulfone (PSF). Thin defect free coating layer can be obtained by appropriate combination of coating solution concentration and support UF membrane porosity. The analysis of effective skin layer thickness of TFC membranes indicated that careful optimization of these parameters is necessary to achieve defect free TFC membranes possessing a good combination of permeance and selectivity. [Copyright &y& Elsevier]

Vibration of a silicon rubber membrane containing a magnetic compound fluid is experimentally investigated. Both the silicon rubber that contains clusters of magnetic particles and the rubber that contains magnetic particles being distributed almost uniformly are oscillated by an impulsive magnetic field. The differences of damping ratio and the maximum displacement of both kinds of the membranes are examined. [ABSTRACT FROM AUTHOR]

In this study a new method is applied to prepare a novel composite in the ethylene propylene diene terpolymer (EPDM)/silicon rubber matrix with dough-modeling compound (DMC) reinforcing. The SEM photos show that the interfacial adhesion between DMC, EPDM, and silicon rubber could be enhanced, and the compatibility and covulcanization of DMC/EPDM/silicon rubber composite are good. The influence of the DMC and peroxide on the mechanical properties and heat resistance are studied. The results show that the mechanical properties and heat resistance of the composite are good, when m DMC/m EPDim silicon rubber is 80/25/75. The heat aging properties of the composite using equivalent dicumyl peroxide (DCP) are better than those using benzoperoxide (BPO), but Shore A hardness and elongation at break do not vary significantly. The integral properties of the DMC reinforced EPDM/silicon rubber composite has advantages over three raw materials. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we prepared MR elastomers containing carbonyl iron particles based on silicon rubber without using a magnetic field during curing by γ-ray radiation. The effects of interactions between iron particles and the matrix on the performance of MR elastomers based on silicon rubber, including MR effect and mechanical properties, were investigated. The rubber/magnetic particle interactions were controlled by the modification of the iron surface using different kinds of silane coupling agents and characterized by SEM and DSC. The results showed that tensile strength increased with the increased interaction. However, the MR effect had a certain relationship with the structure of silane coupling agents and this is discussed in detail in relation to the mechanism of the MR effect. [Copyright &y& Elsevier]

Abstract: A slip analysis has been developed to calculate the slip velocities from the capillary rheometry data for a polydimethylsiloxane (PDMS) gum, and two silicon rubber compounds. The analysis generalises the classical Mooney method [J. Rheol. 2 (1931) 210–222] to incorporate the influence of die geometry on the slip behaviour. For the PDMS gum, no slippage was observed below a stress level of about 60 kPa, and there was a jump in the slip velocity at a stress level of about 80 kPa. The complex rheological behaviour of the rubbers meant that the analysis was only applicable at higher stress levels. For each material, a reasonable fit to the slip velocity was obtained using a generalised Navier slip law, which can easily be implemented into computational fluid dynamic simulations. Ultimately, a more realistic slip law is required to model the observed flow behaviour correctly. [Copyright &y& Elsevier]