• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1503-1506
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• 1997

The main fault in this interface is that power cable insulating materials are mainly composed of a double layered structure, XLPE/EPDM laminates in cable joint. In this paper, we instituted the interface of normal and degassed XLPE/EPDM and then investigated the breakdown and conduction characteristics as a function of heat treatment time. The results showed that conduction and breakdown strength was influenced by volatile crosslinking by-products which remained inside the insulating material during the production of XLPE and EPDM, especially during heat treatment process. And micro voids and surface roughness also influenced the conduction current and breakdown strength.

• Elastomers and Composites
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• 제44권2호
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• pp.134-142
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• 2009

양기능성실란(TESPD)이 실리카가 함유된 NR복합소재에 첨가되었을시 그에따른 가교특성, 가공정도, 물리적 특성들에 미치는 영향을 조사하였다. TESPD를 첨가한 NR복합소재는 TESPD가 실리카표면과 고무의표면을 화학적으로 결합하여 3차원적인 구조를 형성함으로해서 가교도가 증가하였고, 이에따라 기계적강도가 증가하였다. 이 복합소재는 또한 TESPD를 첨가하지않은 소재와 비교했을시 가공성이 증가하는것을 보여주었다.

• 한국전기전자재료학회논문지
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• 제11권9호
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• pp.671-682
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• 1998

Chemical structure and electrical characteristics of 5 commercial crosslinked polyethylenes (XLPE) used as insulating materials for medium voltage distribution power cables in Korea were investigated. It was found that each XLPE shows different properties depending on the type of XLPE. Chemical structural irregularities of pellets change considerably by crossliking reaction, with some irregularities being disappeared after crosslikeng reaction. It was also found through a solvent extraction study that additives such as crosslinking agent and antioxidants act as major source retarding water tree growth. Low molecular weight polyethylene chains plays a different role in water tree growth of XLPE.

• Elastomers and Composites
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• 제44권3호
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• pp.252-259
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• 2009

양기능성실란(TESPD)이 실리카가 함유된 SBR 복합 소재에 첨가되었을 시 그에 따른 가교특성, 가공정도, 물리적 특성들에 미치는 영향을 조사하였다. TESPD를 첨가한 SBR 복합 소재는 TESPD가 실리카와 고무를 화학적으로 결합하여 3차원적인 구조를 형성함으로해서 가교밀도가 증가하였고, 이에 따라 기계적 강도가 증가하였다. 이는 또한 TESPD를 첨가하지 않은 소재와 비교했을 시 가공성이 증가하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.225-228
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• 1997

The main fault in this interface is that power cable insulating materials are mainly composed of a double layered structure, XLPE/FPDM laminates in cable joint. In this parer, we instituted the interface of XLPE/EPDM laminates and then investigated the breakdown and conduction characteristics as a function of heat treatment time. The results showed that conduction current was influenced by volatile crosslinking by-products which remained inside the insulating material during the production of XLPE and EPDM, especially during heat treatment process. And conduction current of XLPE/Oil 12500cSt/EPDM was more stable than XLPE/Grease/EPDM from the long heat treatment time. AC breakdown strength of silicone oil itself from the heat treatment was changed during the 4∼12 hour heat treatment time.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.517-524
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• 2014

Two key technologies of horizontal drilling and hydraulic fracturing are recognized to achieve the rapid growth of shale gas production, in specific, in the United States during last decade. The claims between environmentalists and oil companies have been debating in terms of water contamination. Nowadays, voluntary publication of chemicals from shale gas players are available in the website, FracFocus. This paper introduces chemicals that are currently used in hydraulic fracturing process. Among chemicals, guar gum and guar derivatives are dominantly consumed to increase the viscosity of hydrofracking fluids. The role of additional additives, such as breakers and biocides, is presented by explaining how they cut down the molecular structure of guar gum and guar derivatives. In addition, crosslinking agent, pH controller, friction reducer, and water soluble polymers are also presented.

• Bulletin of the Korean Chemical Society
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• 제6권3호
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• pp.128-131
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• 1985

A series of copolymer membranes of 2-hydroxyethylmethacrylate (HEMA) with selected hydrophobic monomers were prepared without crosslinking agents. The equilibrium water content, the partition coefficient, and the permeability of the solutes such as urea, methylurea, 1,3-di-methylurea, and acetamide via these membranes were measured. The partition coefficient data show that as the hydrophobicity of solutes increased, the partition of solutes were dictated by hydrophobic interaction between solute and polymer matrix. Diffusion coefficients obtained in these experiments decrease as the water content of polymer membrane decreases. This decrease is blunt as the excess heat capacities, ${\phi}C^0_p$ (excess) in aqueous solution at infinite dilution of solute increases. To investigate the relationship between water content and diffusion coefficient, the results of the diffusion experiments were examined in light of a free-volume model of diffusive transport. The remarkable increase of urea mobility in the polymer network containing relatively larger bulk water can be considered as water structure breaking effect.

• 방사선산업학회지
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• 제2권3호
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• pp.105-110
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• 2008

Poly (VDF-co-HFP)/PEGDMA nanofibrous membranes (NFMs) have been prepared by an electrospinning process. Since electrospun NFMs have a nanoporous structure, they have a potential application for a polymer electrolyte or a separator. Poly (VDF-co-HFP) is a polymer electrolyte binder. In order to improve their mechanical properties, poly (VDF-co-HFP)/PEGDMA NFMs were crosslinked by a gamma-ray irradiation. Then the crosslinked NFMs were characterized through an electrolyte uptake, IR structural analysis, and SEM morphological investigation.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.333-336
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• 1999

The polyaniline films with various insoluble parts are fabricated. The oxidation state (1-y) of these polyaniline is 0.53 and 0.54, respectively. To control the interchain and intrachain interaction of the polymer, the polyaniline films are stretched with appropriate ratio. The insoluble part of polyaniline synthesized at room temperature (low molecular weight) is 12%-76% and that of polyaniline synthesized at 0 'IC (intermediate molecular weight) is 65%-89%. The low molecular weight polyaniline films with various drawing ratios have amorphous structure. In the intermediate weight polyaniline films, the crystallinity of films increases with drawing ratio as well as insoluble part. The difference of the insoluble part affects electrical conductivity which is increased dramatically with draw ratio. In particular, the higher insoluble part caused greater increase in electrical conductivity.

• 한국의류학회지
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• 제29권7호
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• pp.987-996
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• 2005

For cationization, if chitosan, which has the affinity for a human body and reacts easily without inducing any pollution, is used, cationization of Tencel blended fabrics can be expected and further expansion of its use as a new susceptible material can be expected. Therefore, in this study, in order to compare a Tencel/cotton and a Tencel/Cotton/PET as Tencel blended fabrics with a Tencel single fabric, the fabric samples were used and processed with chitosan after NaOH pretreatment and enzyme treatment thereof, and then its adherent efficiency was enhanced by using a crosslinking agent, and then it was got to be finished with a softener. The fibril of Tencel fabric was controlled by enzyme treatment so that the surface of the Tencel blended fabrics got to be smooth. Chitosan adhered to the surface of the Tencel blended fabrics in the form of particles through its processing with chitosan. Chitosan treatment caused little change in the crystal structure thereof and the thermal stability of the Tencel/Cotton/PET fabric was slightly improved. The total hand value(THV) calculated on the basis of the change due to chitosan treatment was increased in all samples.