• 콘크리트학회논문집
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• 제17권5호
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• pp.695-702
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• 2005

라텍스개질 콘크리트는 라텍스의 첨가로 인하여 콘크리트의 내구성을 개선하는 것으로 알려져 있으며, 투수저항성이 크게 향상되는 것으로 연구되었다. 본 연구에서는 SBR 라텍스 혼입에 따른 콘크리트 내부 공극 구조의 변화를 연구하고자 화상분석법을 이용하여 라텍스개질 콘크리트의 W/C비, 라텍스 함량, 시멘트 종류에 변화를 주어 간격계수, 경화 후 공기량, 공극 직경에 따른 공극 분포 및 공극 구조 상태 분석 등을 파악하였다. 또한, 라텍스 첨가에 따른 내부 공극 구조 특성과 투수저항성과의 상관성을 비교하였다. 라텍스개질 콘크리트는 내부 공극 분석 결과, 동일 물-시멘트비 조건에서 AE감수제를 사용한 OPC에 비해 더 우수한 연행공극 효과가 있는 것으로 분석되었다. 초속경시멘트는 $100{\mu}m$ 미만의 연행공극의 수가 4배 이상 증가하였다. 조강 시멘트는 SBR 라텍스로 인하여 $50{\sim}500{\mu}m$ 범위의 미세 연행 공기량이 약 7배 이상 증가되는 현상을 나타내었다. 그러나 투수성에 있어서는 낮은 간격계수에도 불구하고 높은 투수저항 특성을 나타내었다. 내구성에 있어서 라텍스개질 콘크리트에서는 공극 구조의 영향보다는 라텍스 폴리머 필름에 의한 영향이 더 큰 것으로 판단되었다.

• 산업기술연구
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• 제21권B호
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• pp.249-256
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• 2001

The purpose of this study was to remove the excessive air foaming which was produced in mixing the RSLMC(latex-modified concrete with rapid-setting cement) by choosing the best antifoam agent type. A series of RSLMM(latex-modified mortar with rapid-setting cement) experiments were carried out as a basic experiments for RSLMC with the main experimental variables such as antifiamer types(A, B, C, D), antifoamer contents(0, 1, 2, 3%), and latex contents(10, 15%). Air content test and compressive strength tests were carried out to measure the improved properties of RSLMM. SEM analysis, also, was carried to observe the formation of latex film. The results of RSLMM showed that the decrease of 50% air content was obtained by admixturing an antifoam agent by 1%. This made the strength enhanced and the workability be within the purposed. The best properties of compressive strengths was obtained at latex content of 15% and D antifoam agent of 1%. compressive strength increased about 32.6%. The analysis of SEM results no difference in a formation of later film.

• 한국응용과학기술학회지
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• 제25권2호
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• pp.115-122
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• 2008

The hydrosilylation is an addition reaction of Si-H bond to unsaturated double bonds, which provides a convenient mechanism to synthesize poly(dimethylsiloxane-co-methylsiloxane)copolymer having siloxy units in polymer backbone. In this study, Poly(dimethylsiloxane-co-methylsiloxane) copolymer was synthesized through the polymerization reaction of cyclopentasiloxane with poly(methyl-hydrogen) siloxane. Silicone-hydrogen functional group of the poly(dimethylsiloxane-co-methylsiloxane) copolymer was substituted to the alkyl groups by hydrosilylation. And their structure was analyzed with FT-IR, H-NMR and GPC instruments, respectively. Surface tension of the synthetic compounds is increased from 22dyne/cm to 25dyne/cm according to increase additional EO moles. The cmc which was evaluated by surface tension was ranged $10^{-5}$ to $10^{-4}mol/L$ and it was decreased according to increase of dimethyl siloxyl content. HLB number of these surfactants was evaluated 9.5 to 11.5 range. These silicone surfactants is applied to self-emulsifier defoamer and personal care products as surface tension depressant, emulsifier, foam control agent.

• 한국응용과학기술학회지
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• 제16권2호
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• pp.147-153
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• 1999

소포제의 주성분으로 소수성 알킬기 탄산수가 12에서 18까지의 고급지방알코올, 고급지방산, 고급지방산에스테르를 사용하였다. 제조한 소포제의 입도분포, 온도, 농도에 대한 소포 특성을 1L/min의 유속하의 ASTM 방식의 Air Injection Method로 측정하였고, 표면장력과 유화력을 측정하였다. 이들 소포제의 입도분포에 대한 소포특성은 입도분포가 $5.5{\sim}6.8{\mu}m$ 범위인 소포제 조성물이 우수한 소포제 특성을 보였다. 묽은 수용액상에서 소포제의 표면장력은 농도가 $10^{-2}$wt%에서 $33{\sim}34$ mN/m 범위였고, 고급 지방산 알코올을 사용한 소포제 조성물의 유화력이 우수하였다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.174-174
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• 2003

There are many synthetic chemicals, such as di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP), used in chemical reaction processes in industry. The establishment of toxicity and detection of synthetic chemicals that may pose a genetic hazard in our enviornment is subjects of great concern at present DEHP, a ubiquitous phthalate plasticizer, induces a wide range of developmental and reproductive toxicities in mammals. DEHP belongs to the large diverse class of peroxisome proliferator compounds, which include herbicides, hypolipidemic drugs. DBP is a plasticizer used to products containing nitrocellulose, polyvinyl acetate, and polyvinyl chloride such as food wraps and blood bags. DBP is also used in cosmetics as a solvent and fixative for perfumes, a suspension agent for solids, an antifoamer, a skin emollient, and hair spray The present study was performed to examine patterns of gene expression in MCF-7 cells following DEHP and DBP exposure. Changes in gene expression were determined by microarray analysis using KISTCHIP-400 including 401 endocrine related genes based on public database and research papers. Of the genes analysis, we determined that genes detected by array showed a 2-fold or greater change in their expression level(increase or decrease). The results of this study demonstrate that a number of genes were differentially expressed in MCF-7 cells but these changes were not significant. Therefore, we keep going this study using microarray analysis and future studies will examine changes of gene expression on time-course and does treatment in variable cell lines.