• Macromolecular Research
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• 제15권6호
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• pp.565-574
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• 2007

In this study, five representative, commercially available polymers, Ultem 1000 polyetherimide, Kapton polyimide, phenolic resin, polyacrylonitrile and cellulose acetate, were used to prepare pyrolyzed polymer membranes coated on a porous {\alpha}-alumina$ tube via inert pyrolysis for gas separation. Pyrolysis conditions (i.e., final temperature and thermal dwell time) of each polymer were determined using a thermogravimetric method coupled with real-time mass spectroscopy. The surface area and pore size distribution of the pyrolyzed materials derived from the polymers were estimated from the nitrogen adsorption/desorption isotherms. Pyrolyzed membranes from polymer precursors exhibited type I sorption behavior except cellulose acetate (type IV). The gas permeation of the carbon/{\alpha}-alumina$ tubular membranes was characterized using four gases: helium, carbon dioxide, oxygen and nitrogen. The polyetherimide, polyimide, and phenolic resin pyrolyzed polymer membranes showed typical molecular sieving gas permeation behavior, while membranes from polyacrylonitrile and cellulose acetate exhibited intermediate behavior between Knudsen diffusion and molecular sieving. Pyrolyzed membranes with molecular sieving behavior (e.g., polyetherimide, polyimide, and phenolic resin) had a $CO_2/N_2$ selectivity of greater than 15; however, the membranes from polyacrylonitrile and cellulose acetate with intermediate gas transport behavior had a selectivity slightly greater than unity due to their large pore size.

• 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.

• 콘크리트학회논문집
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• 제14권1호
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• pp.41-48
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• 2002

본 연구에서는 불포화 폴리에스테르 수지 또는 비닐에스테르 수지를 중량비로서 5~8%, 수지와 충전재의 비 1 : 1, 잔골재량 0~15% 및 입자범위 2.5~10mm의 부순돌을 사용하여 투수성 폴리머 콘크리트를 만든 다음 압축강도, 휨강도 및 투수성을 시험하여 수지와 잔골재의 양이 투수성 폴리머 콘크리트의 물성에 미치는 영향을 구명하였다. 실험결과 수지와 잔골재량이 증가하는데 따라 투수성 폴리머 콘크리트의 강도는 증가하고 투수계수는 저하하였으며, 투수계수 0.1~l.0cm/s를 유지하는 경우 압축 강도는 170~350 kgf/$\textrm{cm}^2$ 그리고 휨강도는 40~90kgf/$\textrm{cm}^2$의 범위를 나타냈다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.96-99
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• 2004

Silica fillers were coated by plasma polymer coatings of 1,3-diaminopropane, allylamine, pyrrole, 1,2-epoxy-5-hexene, allyl mercaptan and allyl alcohol using RF plasma (13.56 MHz). The coated fillers were then mixed with biphenyl epoxy, phenol novolac (curing agent) and/or triphenylphosphine (catalyst), and subjected to DSC analyses in order to elucidate the chemical reaction between functional moieties in the plasma polymer coatings and the epoxy resin. Only the samples with 1,3-diaminopropane and allylamine plasma polymer coated silica fillers showed heat of reaction peaks when they were mixed with biphenyl epoxy resin only, while these samples as well as the samples with 1,3-diaminopropane, allylamine and pyrrole plasma polymer coated silica fillers exhibited heat of reaction peaks when mixed with both biphenyl epoxy and phenol novolac (curing agent).

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.343-348
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• 1999

The purpose of this study is to evaluated the effects of added expanded polystyrene on the basic properties of UP mortar. Polyester resin mortars are prepared with expanded polystyrene ratio in styrene monomer (EPS/PS), and the ratio of total polystyrene resin to UP resin (PS/UP). And it is tested for viscosity of UP resin added PS resin, slump-flow test, working life, flexural and compressive strengths, and curing shrinkage test. From the test result, Viscosity of resin for polymer mortar increases with increasing PS content. Curing shrinkage of UP mortar is considerably smaller than that of plain UP mortar, nevertheless, reduction in the strengths is not recognized according to adding PS resin. In this study, we can obtain the optimum mix proportions of polymer mortar using PS resin.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.255-257
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• 2012

Epoxy resin without any hardener can harden in the presence of hydroxide ions in cement mortars and concretes at ambient temperature. The purpose of present study is to examine the hardening properties of hardener-free epoxy-modified mortars by curing conditions. The hardener-free epoxy-modified mortars using diglycidyl ether of A epoxy resin are prepared with various polymer-cement ratios, and subjected to initial moist/dry curing, initial steam(90℃) curing, initial steam/heat(80℃, 100℃) curing.As a result, degree of hardening of epoxy resin in initial moist/dry cured, initial steam cured and initial steam/heat(80℃) cured hardener-free epoxy-modified mortars is decreased with increasing polymer-cement ratio. However, it is markedly improved with additional dry-curing periods. On the other hand, regardless of the polymer-cement ratio and dry curing periods, degree of hardening of hardener-free epoxy-modified mortars with initial steam/heat(100℃) cure is over 95%.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 추계 학술논문 발표대회
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• pp.55-59
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• 2009

The epoxy resin without hardener can harden by a ring-opening reaction in the presence of the alkalies produced by the hydration of cement in epoxy-modified mortars and concretes. This paper investigates the effect of curing conditions on the strength improvement of polymer-modified mortars using bisphenol A-type epoxy resin without hardener. The polymer-modified mortars using epoxy resin are prepared with various polymer-cement ratios, and subjected to ideal, water, dry and heat cures. In the heat cure, the epoxy-modified mortars are sealed or unsealed with a PVDC (polyvinylidene chloride) film. The epoxy-modified mortars are tested for flexural and compressive strengths at desired curing methods. The microstructures of the epoxy-modified mortars are also observed by scanning electron microscope. The effects of curing conditions on the strength development of the epoxy-modified mortars are examined. From the test results, the marked effectiveness of the heat cure under the PVDC film sealing against the development of the strength of the epoxy-modified mortar without the hardener is recognized. The flexural and compressive strengths of 7-day-90℃ heat-cured, PVDC film-sealed epoxy-modified mortars without hardener reach 7 to 17MPa and 24 to 44MPa respectively, and are two to three times of Unmodified mortar. Such high strength development of the epoxy-modified mortars may be achieved by the dense microstructure formation by cement hydrates and the hardening of the epoxy resin in the mortars.

• 한국정밀공학회지
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• 제22권6호
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• pp.144-151
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• 2005

Spin coater is regarded as a major module rotating at high speed to be used build up polymer resin thin film layer fur bonding process of GaAs wafer. This module is consisted of spin unit for spreading uniformly, align device, resin spreading nozzle and et. al. Specially, spin unit which is a component of module can cause to vibrate and finally affect to the uniformity of polymer resin film layer. For the stability prediction of rotation velocity and uniformity of polymer resin film layer, it is very important to understand the dynamic characteristics of assembled spin coater module and the dynamic response mode resulted from rotation behavior of spin chuck. In this paper, stress concentration mode and the deformed shape of spin chuck generated due to angular acceleration process are presented using analytical method for evaluation of structural safety according to the revolution speed variation of spin unit. And also, deformation form of GaAs wafer due to dynamic behavior of spin chuck is presented fur the comparison of former simulated results.

• 공업화학
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• 제29권2호
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• pp.201-208
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• 2018

올소-타입 불포화폴리에스테르 수지와 이소-타입 불포화폴리에스테르 수지를 합성하여 폴리머 모르타르 복합재료의 폴리머 결합재로 사용하였다. 불포화폴리에스테르 수지의 희석제로는 스티렌 모노머와 아크릴로니트릴을 사용하였고, 경화제로 methyl ethyl ketone peroxide (MEKPO), 가속제로 cobalt octoate (CoOc)를 사용하였다. 수지의 형태와 희석제의 종류에 따라 4종의 불포화폴리에스테르 수지를 제조하여 공시체 제조의 폴리머 결합재로 사용하였다. 폴리머 결합재의 첨가량에 따라 총 16종의 폴리머 모르타르 공시체를 제작하여 내열수성 시험을 행한 후 압축 및 휨강도시험, 세공분석 및 SEM 분석을 실시하였다. 시험결과, 이소-타입 불포화폴리에스테르 수지를 폴리머 결합재로 사용한 공시체가 올소-타입 불포화폴리에스테르 수지를 사용한 공시체보다 더 우수한 강도를 나타내었다. 내열수성시험 후에 측정한 총세공량과 세공의 평균직경은 시험 전에 측정한 값에 비하여 감소되었다. 내열수성시험 전에 관찰한 사진에서 폴리머 결합재와 충전재 및 잔골재가 co-matrix 상으로 견고하게 결합되어 있었으나 내열수성시험 후에 관찰한 사진에서는 폴리머 결합재가 대부분 분해되어 있는 것을 관찰할 수 있었다.

• 한국응용과학기술학회지
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• 제26권1호
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• pp.93-101
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• 2009

Antistatic acrylic resin is made from n-butyl methacrylate, methyl methacrylate, dimethyl amino ethyl methacrylate(DMAEMA), 2-ethyl hexyl methacrylate, hydroxy ethyl methacrylate, 2,2'-azobis iso-butyronitrile by synthesis. To achieve a lowest surface resistance of antistatic acrylic resin was applied to a variety of synthesis processes. The acrylic resin has been determined from the value of surface resistance and -then the antistatic acrylic resin including dimethyl amino ethyl methacrylate of the 10%, 20% and 30% is synthesized. Finally, dimethyl sulfate(DMS) on a variety of weight ratios is added to antistatic acrylic resin. When DMAEMA / DMS weight ratio is 1/1, antistatic acrylic resin isn't haze the lower the surface resistance. Compared to the traditional antistatic agent, all aspects of the physical properties is outstanding.