• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.247-252
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• 2009

The LMC method of construction which have application to the road bridge is being considered the least relative importance about the watertight performance, because it focused on the durability of concrete. However, The LMC which is being expanded scope of application to the method of construction has grown importance about the watertight performance on the usability and maintenance side as well as durability. In this study, The latex concrete of two types which are different from mingled-ratio of the latex made a comparison to the compressive strength, watertight performance, dynamic wheel load resistance performance and confirmed what it has resistibility about chemical action through the chemical resistance test. The initial strength and watertight performance showed that were tendency the downward at 14 days. However, The long-term strength after 28 days showed that it has firm performance. In consequence, The initial curing of latex concrete is required to scrupulous care and attention at the site application. As a chemical resistance test result, The specimen that is steeped in sulphuric acid solution of 2% discovered the delamination phenomenon. However, it was confirmed that delamination phenomenon don't have an effect on the compressive strength. Moreover, As a dynamic wheel load resistance test result, The latex concrete was concluded to confirming the durability and running stability, because it had hardly any thickness reduction of latex concrete surface about dynamic wheel load and rarely found crack and delamination.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.1011-1016
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• 2001

The purpose of this study is to find out the effect of polymer glass transition temperature on mechanical properties of polymer latex-modified mortars in comparison with ordinary cement mortar. The Polymer latex-modified mortars are prepared with 5, 10, 15 and 20% of polymer cement ratio respectively, and properties of modified mortars such as air content, compressive, flexural and tensile strengths are tested. The test results indicate that the types of polymer dispersion and the polymer-cement ratio are very important factors to characterize the properties of polymer-modified mortars, and also the glass transition temperature of polymer dispersions has an important effect on the performance of polymer-modified mortars. The modifying effects of two kinds of polymer dispersion, St/BA-1 and SBR, are evaluated.

• 한국응용과학기술학회지
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• 제21권3호
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• pp.259-266
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• 2004

Film properties of monodispersed model composite latexes with particle size of 190 nm, which consist of n-butyl acrylate as a soft phase monomer and methyl methacrylate as a hard phase monomer with different morphology was examined. Five different types of model latexes were used in this study such as random copolymer particle, soft-core/hard-shell particle, hard-core/soft-shell particle, gradient type particle, and mixed type particle. Tensile strength and tensile elongation at break of final films were evaluated. Those properties can be interpreted in terms of PBA/PMMA phase ratio and their morphology. The interfacial adhesion strength was also evaluated using $180^{\circ}$ peel strength measurement and cross hatch cutting test.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.51-57
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• 1996

The purpose of this study is to improve the properties by increasing of the adhesion strength of styrene-butadiene rubber(SBR) latex coated powdered rubber in cement mortar. SBR-modified mortar using powdered rubber is also tested as the same method. From the test results, the cement mortar using SBR latex coated powdered rubber have a good mechanical properties compared with that using uncoated powdered rubber. The mechanical properties of SBR-modified mortar using powdered rubber with polymer-cement ratios of 10% are also improved.

• 펄프종이기술
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• 제47권1호
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• pp.10-16
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• 2015

Bio-binder is well known as a promising alternative binder for SB latex because it is eco-friendly and inexpensive, compared to synthetic latex. SB latex in top coating color was substituted with starch-based bio-binder to investigate its effects on the coating color and its coated paper properties. Bio-binder contributed to the increase of coating color viscosity, and the improvement of water retention. Most optical properties except opacity were deteriorated by the increase of bio-binder dosage. It was also found that the increase of bio-binder substitution in top coating color brought about the increase of roughness, and decrease of coated paper gloss, print gloss, dry and wet pick strength. However the stiffness and the ink set-off of the bio-binder coated paper were improved. Overall, mostly adverse effects of bio-binder on the properties of coating color and its paper were observed. Therefore, it is not recommended to use bio-binder as top coating color.

• 대한토목학회논문집
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• 제26권1A호
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• pp.205-211
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• 2006

본 연구에서는 플라이애쉬 혼입률에 따른 라텍스개질 콘크리트의 역학적 특성과 내구성을 평가하였다. 이를 위해 라텍스 혼입률 변화(0%, 10%, 15%)와 플라이애쉬 혼입률 변화(0%, 10%, 20%, 30%)를 주 실험변수로 하여 평가하였다. LMC와 FA-LMC의 특성분석을 위하여 압축강도, 휨강도 그리고 황산 및 염산에 의한 내약품성 시험을 실시하였다. 실험결과, 플라이애쉬를 혼입한 라텍스 개질 콘크리트에 있어서, 플라이애쉬 혼입률이 증가함에 따라 공기량은 감소하는 것으로 나타났다. 그리고 FA-LMC의 압축 및 휨강도는 라텍스 개질 콘크리트(LMC)와 유사한 강도발현 특성을 보이며, 장기재령에 있어서는 FA-LMC가 LMC에 비해 높은 휨강도 발현특성을 보였다. 그리고 투수특성에 있어서 플라이애쉬의 혼입률이 증가할수록 투수저항성이 증가하였으며, 내화학약품성에 대한 저항성도 증진되는 것으로 나타났다. 따라서, 플라이애쉬는 LMC의 혼화재로서 투수저항성을 증진시킬 목적으로 효과적으로 사용될 수 있을 것이다.

• 콘크리트학회논문집
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• 제15권1호
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• pp.95-101
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• 2003

상대적으로 큰 비표면적으로 인해 야기될 수 있는 건조수축균열은 보통 포틀랜드시멘트를 사용한 라텍스개질 콘크리트(LMC) 및 초속경 시멘트를 사용한 라텍스개질 콘크리트(RSLMC) 덧씌우기에서 주요 관심사항이다. 우리나라에서는 LMC와 RSLMC의 현장 적용을 위해 강도와 내구특성 측면에서 활발히 연구되어 왔으나 건조수축특성에 관한 연구는 전무한 상태이다. 따라서, 본 논문의 목적은 LMC와 RSLMC의 건조수축특성에 관하여 시멘트 종류(보통 포틀랜드 시멘트, 초속경시멘트), 라텍스 혼입률(0, 5, 10, 15, 20%)을 주요 실험 변수로 하여 연구하고자 하였다. 양생방법으로는 60%의 상대습도와 $20^{\circ}C$의 온도로 하였으며, 건조수축용 시편은 디지털 Demec 게이지로 측정하였다. 실험 결과를 통하여 LMC와 RSLMC의 건조수축량은 OPC와 RSC보다 상당히 감소되는 것으로 나타났다. 이것은 콜로이드같은 라텍스의 특성이 수분 증발을 억제함으로써 향상되는 보습성과 라텍스 필름막에 의한 시멘트 수화물과 골재간의 상호연결작용으로 기인되는 것으로 판단된다.

• Elastomers and Composites
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• 제37권1호
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• pp.21-30
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• 2002

개시제 ammonium persulfate(APS)와 유화제 sodium dodecyl benzene sulfonate(SDBS)를 이용하여 methyl methacrylate(MMA), styrene(St), ethyl acrylate(EA)등의 단량체를 core(내부)와 shell(외부)의 폴리머성분이 다른 core-shell 폴리머를 합성하고 각 core-shell 폴리머에 대한 구조를 연구하였다. 한 입자의 내부와 외부의 고분자 조성이 다른 composite 라텍스는 고분자 블렌딩과 공중합의 물성과는 달리 한 입자 내에서도 상반된 두 가지 물성을 동시에 나타내는 특성으로 인하여 여러 산업 분야에 응용이 가능하다. 그러나, core-shell 라텍스를 제조할 때 반응중입자가 성장하는 과정에서 입자의 응집과 중합율이 떨어지고, 라텍스의 응용시 기계적 안정성이 문제점으로 되고 있다. 따라서 shell 중합시에 새로운 입자의 생성이 적고 중합중 안정성이 우수한 라텍스를 제조하기 위해 유화제농도, 개시제농도, 중합온도가 PMMA/PSt과 PSt/PMMA의 core-shell 구조에 미치는 영향과 중합 후 입도분석기(particle size analyzer; PSA) 및 투과전자현미경(transmission electron microscope; TEM)을 이용하여 실제 입자측정과 입자형태 특성을 확인하였으며 시차주사열량계(differential scanning calorimeter, DSC)를 이용하여 유리전이온도($T_g$)의 측정, 최저성막온도(minimum film formation temperature; MFFT), NaOH 첨가에 의한 가수 분해에 따르는 pH를 측정하여 core-shell의 새로운 특성을 확인하였다.

• 펄프종이기술
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• 제32권3호
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• pp.39-47
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• 2000

This study was carried out to investigate the effect of the type of base papers containing Sw-BDP, HW-BDP and Bamboo-BKP on the properties and printabilities of coated papers. Also it was intended to evaluate the effect of coated paper prepared with anionic and amphoteric latex based coating color. The results obtained from this study were as follows. The fiber length of Bamboo-BKP was observed longer than that of the Hw-BKP and shorter than that of the Sw-BKP. This has effect on physical properties. Therfore the results of mea-suring physical properties were higher ratio of Sw-BKP physical properties tended to be slightly higher with the increase I the mixing ratio. Considering the optical properties of base papers the highest opacity was obtained in case of the Hw-BKP and the second appeared Bamboo-BKP. On the other hand smoothness roughness and air permeability of Bamboo-BKP were lower than those of wood pulp and the optical properties of coated papers tended to show the similar with those of base papers. The ink receptivity and print gloss of the coated papers for Bamboo-BKP were lower than those of wood pulp. As the mixing ratio of Sw-BKP was increased the properties and printabilities were improved slightly. Meanwhile amphoteric latex was improved the optical properties and printability of coated papers.

• Elastomers and Composites
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• 제54권2호
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• pp.91-96
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• 2019

The purpose of this study was to examine the effect of different yarn twisting methods on physical properties. Plain single jersey structured fabrics were knitted from Kevlar yarn, and from Kevlar/HPPE, and from Kevlar/Basalt fiber, and from Kevlar/Glass fiber and Kevlar/Stainless steel fiber blended and core-spun yarns. and then, The fabrics were coated NBR Latex. The physical properties, including tear strength, modulus, degree of penetration, heat resistance, and cut resistance of the knitted fabrics were investigated and compared. Kevlar/HPPE blended yarn fabrics recorded the highest heat resistance (13 Sec.). and Kevlar/HPPE blended yarn fabrics had good cut resistance (Cut Level 4).