• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.330-335
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• 1998

This research was conducted to evaluate the adhesion in tension of the polymer mortars for cement concrete repair. Various polymer types, binder ratios, and wet/dry conditions of the surface were considered in this study. Styrene-butadiene rubber (SBR) and ethylen vinyl acetate (EVA) used for polymer cement mortars. Epoxy resin (EP), and unsaturated polyester resin (UP) were used for polymer mertars. Adhesion in tension for the dry condition of the substrate surface was higher than that for the wet condition of the substrate surface under the same binder ratio. Therefore, in repairing concrete, the dry surface condition was effective on adhesion.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.189-192
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• 2001

Resin transfer molding process has been widely used in the automobile industry, because the product with large area can be manufactured easily and the cost for the manufacturing is lower than that of compression molding and hand lay up method. Since RTM process is suitable for large bus housing panels, in this work, the composite housing panel was manufactured by RTM process and the mechanical properties, surface quality and the condition of manufacturing process were studied.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 봄 학술발표회 논문집
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• pp.1-4
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• 1990

This study was conducted to evaluate strength characteristics of various polymer concretes which were produced using materials available in Korea. Compressive strength, splitting tensile strength and flexural strength were evaluated in this study. Eight different polymer binders were used, including two types of epoxy resin, five types of unsaturated polyester resin, and a type of MMA monomer. The results of this study showed that the product made from PC-100 of SH company was the best performing concrete. However, since this result was based on strength and economics point of view, further study has to be conducted for comprehensive analysis.

• 대한전기학회논문지
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• 제41권2호
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• pp.178-184
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• 1992

This study treats the improvement of the dielectric strength of polymer by eliminating the air in it and dissolving electronegative gases. As experimental material, unsaturated polyester resin was used and the specimen was made by dissolving NS12T. SFS16T abd CCIS12TFS12T gases which have strong electron affinity. And also the electrical properties (tree growth and breakdown characteristics) of them were tested and discussed. The results are as follows. When the specimen dissolved with electronegative gas compared with one with air` 1) The tree breakdown voltage of the former is higher than that of the latter. 2) The tree growth of the former is slower than that of the latter. 3) The temperature dependence of the former is smaller than that of the latter. 4) The breakdown voltage of the specimen dissolved with electronegative gas is much higher than that dissolved with air.

• Advanced Composite Materials
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• 제16권3호
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• pp.195-206
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• 2007

Carbon nanofiber (CNF)/unsaturated polyester resin (UPR) was prepared by a solvent evaporation method, and the temperature dependency of electrical conductivity was investigated. The CNF/UPR composites had quite a low percolation threshold due to CNF having a larger aspect ratio and being well dispersed in the UPR matrix. The positive temperature coefficient (PTC) was found in the CNF/UPR composites and it showed stronger effect around the percolation threshold. The electrical resistance of the CNF/UPR composites decreased and had lower temperature dependency with increasing numbers of thermal cycles.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.840-845
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• 2003

Polymer concrete (PC) using unsaturated polyester resins based on recycled polyethylene terephthalate (PET) plastic waste were used in our study for grasping its mechanical properties such as compressive strength, tensile strength and flexural strength, etc. by changing its quantity of resin, filler and dilution(SM) respectively. As a result of it, compressive, tensile and flexural strength of PC indicated 752kgf/$cm^2$, 80kgf/$cm^2$, and 243kgf/$cm^2$, kind of satisfaction successively. Judging from the above results, polymer concrete (PC) using unsaturated polyester resins as a coupling are suitable for construction material both in the aspect of ECO-building materials and in the aspect of superior strength of PC so that it is good possibility of success as a product.

• 공업화학
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• 제10권1호
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• pp.93-97
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• 1999

불포화폴리에스테르 수지의 표면에너지를 저하시키기 위하여 실록산-에스터 공중합체를 소량 첨가하였다. 실록산-에스터 공중합체는 diol로써 ethylene glycol(EG)과 hydroxy terminated polydimethylsiolxane(PDMS)을, diacid로써 maleic anhydride (MA)와 phthalic anhydride (PA)를 축중합반응 시켜 합성하였다. 경화된 블렌드의 표면성질은 동적접촉각(dynamic contact angles)측정, 점착테이프의 peel 강도측정 및 X-ray photoelectron spectroscopy (ESCA)등을 통하여 분석하였다. 블렌드에서 공중합체의 첨가량이 증가하고, 공중합체내의 PDMS 함량이 증가함에 따라 물에 대한 advancing 접촉각 및 receding 접촉각이 증가하였으며, 점착테이프의 peel 강도는 급격히 감소하였다. ESCA 분석결과 실록산 세그멘트가 공기쪽 표면층에 주로 존재하고 있음을 알 수 있었다.

• 한국농공학회지
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• 제45권1호
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• pp.45-54
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• 2003

The effects of binder content and silica sand content on the durability characteristics of lightweight polymer concretes are examined. As a result, the flame lingering times using unsaturated polyester resin and non-combustible polyester resin were 60∼120 and 0∼4 seconds respectively, and the combustion lengths were 9∼11 mm and 0∼3 mm, respectively. Thus it is believed that the lightweight polymer concrete was incombustible and the light weight polymer concrete in which non-combustible material was added was perfectly non-combustible. The percent of original mass of lightweight polymer concrete, according to the freezing-thawing experiment, was below 0.3 %, which was much less than that of cement concrete. The pluse velocity, for the case of the binder content 28 %, showed the minimum decreasing rate for the lightweight polymer concrete with silica sand content of 50 %. The higher the binder content, the greater the durability. That is much higher than other material and believed that the freezing-thawing was suppressed by a low absorption.

• 한국안전학회지
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• 제6권3호
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• pp.12-20
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• 1991

The dielectric properties that effect to electric safety for unsaturated Pelvester resin were studied over the temperature range of 30-40［$^{\circ}C$］ and the frequency range of 110~3$\times$10$^{6}$ ［Hz］. According to the results of the study, it has been observed that two kinds of dielectric losses in electric safety were existed by the molecular movement of C-H and OH group. When the ,adio of hardener was 1.5［%］, the characteristics of specimens were excellent in view of the electrical materical. In the range of measuring frequency the dielectric constants and the dielectric losses were 3.5~5.5 and 10$^2$~10$^3$ respectly. The activation energy of loss spectrum in aspect of electric safety and the entropy appeared at the 30［$^{\circ}C$］ were 33.4［Kacl/mole］ and 54.9［cal/mole.deg］ respectly.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.324-327
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• 2004

In this paper, fundamental properties of Polymer Concrete made from unsaturated polyester resin based on recycled PET and recycled aggregate(RPC) were investigated. Resins based on recycled PET and recycled aggregate offer the possibility of low source cost for forming useful products, and would also help alleviate an environmental problem and save energy. The results of test for resin contents and recycled aggregate ratio are showed that the strength of RPC increases with resin contents relatively, however beyond a certain resin content the strength does not change appreciably, and the relationship between the compressive strength and aggregate contents at resin $9\%$ has a close correlation linearly whereas there is no correlation between the compressive strength and the flexural strength of RPC with recycled concrete aggregate.