• Elastomers and Composites
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• v.44 no.3
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• pp.260-268
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• 2009

Modification of clay surface was attempted by treating the clay with bis[(3-triethoxysilylpropyl)tetra sulfide (TSS) to raise the hydrophobicity and to induce a chemical reaction between the clay and the high temperature vulcanization-type silicone rubber matrix with purpose of improving the compatibility between the components, and thereby Na-$MMTS_4$ and Fe-$MMTS_4$ were synthesized by treating Na-MMT and Fe-MMT with TSS, respectively. Silicone rubber/clay composites were prepared by compounding the clays with silicone rubber. Thermal stability and mechanical properties were evaluated as a function of the clay types and the surface modification.

• Elastomers and Composites
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• v.54 no.2
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• pp.142-148
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• 2019

In this study, the effects of filler particle size and shape on the physical properties of silicone rubber composites were investigated using inorganic fillers (Minusil 5, Celite 219, and Nyad 400) except silica, which was already present as a reinforcing filler of silicone rubber. Fillers with small particle sizes are known to facilitate the formation of the bound rubber by increasing the contact area with the polymer. However, in this experiment, the bound rubber content of Celite 219-added silicone composite was higher than that of Minusil 5-added silicone composite. This was attributed to the porous structure of Celite 219, which led to an increase in the internal surface area of the filler. When the inorganic fillers were added, both thermal decomposition temperature and thermal stability were improved. The bound rubber formed between the silicone rubber and inorganic filler affected the degree of crosslinking of the silicone composite. It is well-known that as the size of the reinforcing filler decreases, the reinforcing effect increases. However, in this experiment, the hardness of the composite material filled with Celite 219 was the highest compared to the other three composites. Furthermore, the highest value of 2.19 MPa was observed for 100% modulus, and the fracture elongation was the lowest at 469%. This was a result of excellent interaction between Celite 219 filler and silicone rubber.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.6
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• pp.640-651
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• 1992

This paper describes the electric properties of mica reinforced silicone composites with the parameter of curing condition of silicone resin, application amount of silane coupling agent to the mica paper and the mica wt% to the composite. Heat-resistant silicone resin and mica paper made of mica flakes are used to prepared the mica/silicone composite as matrix and filler, respectively. To improve the dielectric properties and interfacial adhesion between matrix and filler, silane coupling agent is applied on the mica paper. As for matrix, tan$\delta$ value of 30$0^{\circ}C$ heat-treated silicone resin is the lowest under 1%. The optimal wt% of coupling agent is 0.3% to the weight of mica paper. 80 wt% of mica as filler to the mica/silicone composite shows the best electric properties. And the mica reinforced silicone composite shows good high-frequency and mechanical tensile stress properties.

• Elastomers and Composites
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• v.38 no.3
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• pp.227-234
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• 2003

Silicone composites for high voltage insulator (HVI SC) were prepared by adding aluminum trihydrate(ATH) treated by surface treatment agent to base silicone compound at the ratio oi 100:20, 100:40, 100:60, 100:80, and 100:100, respectively And also, ATH was treated by various surface treatment agents, such as stearic arid, acryl silane, and vinyl silane under compounding process. Mechanical properties and electrical properties were investigated for the various contents of ATH and surface-treatment agents. Mechanical properties such as tensile strength, elongation, and tear strength decreased as the load of ATH increased. Volume resistivity, AC break down strength, and tracking resistance for HVI SC containing ATH treated by vinyl silane were better than those for HVI SC containing ATH treated by other surface treatment agents, such as stearic acid and acryl silane. Polymer-filler interaction of silicone composites according to surface treatment agents was studied by measuring bound rubber contend(BR). From the experimental results, BR of silicone composite containing ATH treated with vinyl silane was higher than that of the others. The degree of rule for silicone composite was investigated using Rheometer. Maximum torque of silicone composites contaning ATH treated with vinyl silane was higher than that of silicone composite contaning ATH treated with other surface agents.

• Transactions on Electrical and Electronic Materials
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• v.7 no.3
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• pp.134-140
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• 2006

The effect of surface treatment of fillers on the mechanical, electrical properties, and tracking performance of silicone rubber insulators have been investigated. For base polymer, $\alpha,\;\omega$) vinyl poly(dimethyl-methylphenyl) siloxane(VPMPS) containing dimethyl siloxane and methylphenyl siloxane was prepared by the equilibrium polymerization. High voltage silicone rubber composites(HVSRC) were prepared from VPMPS, nano-silica, and alumina trihydrate (ATH) modified by various coupling agents. Bound rubber of uncured silicone rubber, cross-linking density of the vulcanizate as well as the mechanical, electrical properties, and tracking performance were measured.

• Elastomers and Composites
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• v.46 no.2
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• pp.164-170
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• 2011

In this study, silicone rubber filled with environmentally-friendly perlite was prepared by mechanical mixing in order to improve thermal properties, such as heat and fire resistances. We found that the properties of silicone rubber composites depended on perlite concentration by various characterization methods. Thermogravimetric analysis(TGA) indicated that the initial degradation temperature of silicone/perlite composite was higher than that of pristine silicone rubber. The gas torch test showed that the opposite side temperature of composite materials was remarkably low as compared to that of pristine silicone rubber. In addition, the composites containing 5 wt% and 10 wt% of perlite showed remarkable thermal stability at elevated temperatures according to the results of both fireproof furnace tests under the RABT condition and carbonization furnace tests. The images from a scanning electron microscope(SEM) showed the degree of dispersion of perlite in silicone rubber. Finally, it was confirmed that limited oxygen index(LOI) was increased with perlite concentration.

• Elastomers and Composites
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• v.51 no.4
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• pp.269-274
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• 2016

Two different reactive silicone oligomers, hydroxylpropyl terminated PDMS (PDMS-L) and 1-(2,3-dihydroxy-propoxy)propyl terminated PDMS (PDMS-B), were synthesized through hydrosilylation reaction under Karstedt's catalyst. Using the reactive silicone oligomers, two different silicone-modified gel-coat series were prepared to investigate their thermal and mechanical properties as well as surface characteristics according to reactive silicone oligomer contents. In case of thermal stabilities and mechanical properties, the gel-coat series containing PDMS-B showed higher values than that of the gel-coat series containing the PDMS-L. The contact angle for the gel-coat containing both silicone oligomers/was increased with reactive silicone oligomer contents but there was similar surface tension between PDMS-L and PDMS-B.

• Elastomers and Composites
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• v.56 no.4
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• pp.209-216
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• 2021

In this study, we observed the mechanical properties, thermal stability, and low temperature sealing performance of fluorosilicone elastic composites. When the blend ratio of Phenyl vinyl methyl silicone (PVMQ) was increased, the tensile strength, modulus at 100%, and compression set were decreased. The thermal stability of fluorosilicone elastic composites showed a similar tendency. These were caused by poorer green strength of PVMQ than Fluorosilicone rubber (FVMQ). The change in the tensile strength and elongation at -40℃ showed a decreasing tendency with increasing PVMQ blend ratio. By increasing the PVMQ blend ratio, low-temperature performance was improved. The Dynamic mechanical analysis (DMA) results showed that T_g was decreased and low-temperature performance was improved with increasing PVMQ blend ratio. However tanδ was decreased becaused of the poor green strength and elasticity of PVMQ. From a hysteresis loss at -40℃, the hysteresis loss value was increased and fluorosilicone elastic composites showed the decreasing tendency of elasticity with increasing PVMQ blend ratio. From the TR test, TR10 was decreased with increasing PVMQ blend ratio. FS-4 (45% PVMQ blended composites) showed a TR10 of -68.0℃ that was 5℃ lower than that of FS-1 (100% FVMQ). The gas leakage temperature was decreased with increasing PVMQ blend ratio. The gas leakage temperature of FS-4 was -69.2℃ that was 5℃ lower than that of FS-1. Caused by the polymer chain started to transfer from a glassy state to a rubbery state and had a mobility of chain under T_g, the gas leakage temperature showed a lower value than T_g. The sealing performance at low temperature was dominated by T_g that directly affected the mobility of the polymer chain.

• Elastomers and Composites
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• v.18 no.1
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• pp.21-29
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• 1983

• Elastomers and Composites
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• v.7 no.2
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• pp.156-159
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• 1972