• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2364-2367
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• 1999

Polymer insulating materials are widely used in power distribution and transmission systems for their good dielectric properties, light weight, low cost, and good contamination performance. Tracking is one of the biggest problems to be overcome in polymer insulating materials. The alumina trihydrate(ATH) is widely used as a filler for improve the tracking performance of silicone rubber. In this paper, we have investigated the influence of surface treatment of fillers on the tracking performance of silicone insulator using the IEC 587 tracking test method.

• Journal of Pharmaceutical Investigation
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• v.21 no.4
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• pp.237-245
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• 1991

Matrix type silicone rubber devices were designed for long-term implantable drug delivery system. Release controlling agents (RCA), i.e., polypropylene glycol, polyethylene glycol, were employed to control drug release from the devices. The release rate of drug from RCA dispersed silicone matrices was mainly dependent on hydrophilicity-hydrophobicity of drug and RCA. In the case of hydrophilic drug, the release from the RCA dispersed matrix was regulated by swelling kinetics. Especially when the relatively hydrophobic polypropylene glycol was used, swelling control mechanism induced zero-order release kinetics. Whereas, the release of hydrophobic drug was resulted from partition mechanism. The effect of RCA was to increase drug diffusivity.

• Steel and Composite Structures
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• v.44 no.5
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• pp.741-752
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• 2022

Earlier works have shown that excessive shear stiffness at the steel-concrete interface causes a non-uniform distribution of shear force in composite structures. When the shear studs are wrapped at the fixed end with flexible materials with a low elastic modulus, the shear stiffness at the interface is reduced. The objective of this study was to investigate the effect of silicone rubber-sleeve mounted on shear studs on the shear stiffness of steel-concrete composite structures. Eighteen push-out tests were conducted to investigate the mechanical behavior of silicone rubber-sleeved shear stud groups (SRS-SSG). The dimension and arrangement of silicon rubber-sleeves (SRS) were taken into consideration. Test results showed that the shear strength of SRS-SSG was higher than that of a shear stud group (SSG), without SRS. For SRS-SSG with SRS heights of 50 mm, 100 mm, 150 mm, the shear strengths were improved by 13%, 20% and 9%, respectively, compared to the SSG alone. The shear strengths of SRS-SSG with the SRS thickness of 2 mm and 4 mm were almost the same. The shear stiffness of the SRS-SSG specimens with SRS heights of 50 mm, 100 mm and 150 mm were 77%, 67% and 66% of the SSG specimens, respectively. Test results of specimens SSG-1 and predicted values based on the three design specifications were compared. The nominal single stud shear strength of SSG-1 specimens was closest to that calculated by the Chinese Code for Design of Steel Structures (GB50017-2017). An equation is proposed to consider the effects of SRS for GB50017-2017, and the predicted values based on the proposed equation agree well with the tested results of SRS-SSG.

• Archives of Plastic Surgery
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• v.33 no.2
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• pp.219-224
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• 2006

Augmentation rhinoplasty is one of the most popular aesthetic procedure in Asians. Numerous alloplastic implants have been used until now, but no accurate comparative analysis about the implant materials has been reported yet. This study in animal model was designed to determine the safety and effectiveness of various implant materials in augmentation rhinoplasty. The $15{\times}15{\times}2mm$ sized square shaped plate of $Gore-Tex^{(R)}$, silicone rubber, and $15{\times}15{\times}1.5mm$ sized $Medpor^{(R)}$ were implanted under panniculus carnosus of the abdomen wall of rat. And tissue specimens including the implant and surrounding soft tissue were obtained by en bloc excision in 6 months after implantation. The implants were estimated in weight and volume, and also the specimens were examined grossly and microscopically. The results revealed that increase of average weight 26.9%, decrease of average volume 55.4% in $Gore-Tex^{(R)}$ implant, increase of each average weight and volume 62.6%, 8.7% in $Medpor^{(R)}$ implant and very slight increase of both average weight and volume 4.7%, 1.1% in silicone rubber implant. Grossly, the $Gore-Tex^{(R)}$ was deformed, $Medpor^{(R)}$ was strongly adherent to surrounding soft tissue and the silicone rubber was well encapsulated and easily peeled off. Microscopically, silicone rubber showed foreign body reaction slightly and there were no inflammatory responses in all alloplastic implants. In our study, silicone rubber showed very proper alloplastic features for augmentation rhinoplasty due to causing no inflammatory response, no physical change, and no deformity.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1367-1369
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• 1994

Recently composite insulators have been In the spotlight because they have many good characteristics as a outdoor insulator for high voltage. The long term properties in composite insulator depend on shed materials. Silicone rubber out of some candidates of shed material has been obtaining good credit from the long term test in field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.501-504
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• 1997

We investigated the tracking and erosion resistance of the silicone rubber by Inclined-Plane Method. And. with the variation of experiment time, the chance of the leakage current waveform was evaluated. The typical leakage current waveform was the form of mixture of sinusoidal wave and rectifying wave. It is thought that the sinusoidal wave is due to conductivity of contaminant when wet. and the rectifying wave is due to arc of dry band.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1332-1336
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• 2016

• 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.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.233-245
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• 1992

The purpose of this study was to evaluate the demensioal stability and wettability of several rubber impression materials. Impressions were made from a metal master die machined to stimulate five full veneer crown preparations symmetrically placed in an arch form. Cast from impressions were measured about ; 1) intrapreparation distance 2) lower base diameter 3) length. For comparing materials were formed against a smooth surface. The advancing contact angle of a saturated aqueous solution of $CaSO_4$ on the impression materials was measured after 1 minute. Mean contact angle were calculated and results were analyzed. Results were as follows : 1. As the intrapreparation distance, hydrophilic addition-cured silicone had the smallest change and condensation-cured silicone had the largest one. 2. As the lower base diameter, traditional addition-cured silicone had the smallest change and polyether had the largest one. 3. As the height, traditional addition-cured silicone had the smallest change and polyether had the largest one. 4. As the contact angle, polyether had the smallest change and condensation-cured silicone had the largest one.

• JOURNAL OF ELECTRICAL WORLD
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• no.3 s.87
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• pp.38-43
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• 1984