• Title, Summary, Keyword: polymer modifier

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A study on the Water Retention of Coating Colors(V)-Application of Alkali Sensitive Water Retention and Rheology Modifiers- (도공액의 보수성에 관한 연구(제5보)-알칼리 반응형 보수.유동성 개량제의 적용-)

  • 이용규;엄기용
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.29 no.4
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    • pp.28-35
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    • 1997
  • Sole-binder formulation has been recently introduced to solve the problems of coating process and printability caused by use of natural polymer However, the decrease of natural polymer application causes another problem in paper coating. Therefore, synthetic thickener is used to get similar effect to natural polymer usage. In this study. low shear viscosity, dewatering of coating colors were measured to evaluate the performance of the alkali sensitive water retention and rheology modifiers. The effects of alkali sensitive thickener on the physical properties of coated paper and printability were also investigated. The gloss and printability of coated paper containing the synthetic flow modifier were similar or superior to those of CMC containing coated paper. This modifier was also effective to improve the problems caused by the use of starch. The results indicated that the flow modifier synthesized with alkali sensitive thickener can reduce the problems of natural polymer and could be a good substitute f3r a natural polymer.

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Performance Improvement of Polymer Light Emitting Diodes by Insertion of a Silane Layer

  • Lee, Jun-Yeob
    • Journal of Information Display
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    • v.8 no.3
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    • pp.1-4
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    • 2007
  • The influence of a silane layer on the performances of polymer light emitting diode(pLED)s has been studied. Glycidoxypropyltrimethoxysilane(GPS) with an epoxy functional group was used as a surface modifier for ITO substrates. The GPS layer was inserted between an ITO and a poly(3,4)-ethylenedioxythiophene/polystyrenesulfonate(PEDOT) by wet process and the performances of PLEDs were investigated. The introduction of GPS layer increased the brightness and efficiency of PLEDs by 30%. In addition, the lifetime of PLEDs was also improved considerably by using GPS as a surface modifier.

Development of Novel Composite Powder Friction Modifier for Improving Wheel-rail Adhesion in High-speed Train (고속열차 점착계수 향상을 위한 신규 복합재료 분말 마찰조절재 개발 및 점착력 특성 평가)

  • Oh, Min Chul;Ahn, Byungmin
    • Journal of Korean Powder Metallurgy Institute
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    • v.25 no.6
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    • pp.501-506
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    • 2018
  • With the recent remarkable improvements in the average speeds of contemporary trains, a necessity has arisen for the development of new friction modifiers to improve adhesion characteristics at the wheel-rail interface. The friction modifier must be designed to reduce slippage or sliding of the trains' wheels on the rails under conditions of rapid acceleration or braking without excessive rolling contact wear. In this study, a novel composite material consisting of metal, ceramic, and polymer is proposed as a friction modifier to improve adhesion between wheels and rails. A blend of Al-6Cu-0.5Mg metallic powder, $Al_2O_3$ ceramic powder, and Bakelite-based polymer in various weight-fractions is hot-pressed at $150^{\circ}C$ to form a bulk composite material. Variation in the adhesion coefficient is evaluated using a high-speed wheel-rail friction tester, with and without application of the composite friction modifier, under both dry and wet conditions. The effect of varying the weighting fractions of metal and ceramic friction powders is detailed in the paper.

Physical Properties of Polymer Modified Mortar Containing FRP Wastes Fine Powder (폐FRP 미분말을 사용한 폴리머 시멘트 모르타르의 물성)

  • 황의환;한천구;최재진;이병기
    • Journal of the Korea Concrete Institute
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    • v.14 no.2
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    • pp.190-198
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    • 2002
  • In this research the physical properties of polymer modified mortar containing pulverized FRP(Fiber-Reinforced Plastics) wastes fine powder as a part of fine aggregate were investigated. Styrene-butadiene rubber(SBR) latex, polyacrylic ester(PAE) emulsion and ethylene-vinyl acetate(EVA) emulsion were used as Polymer modifier. Polymer modified mortars containing FRP wastes fine powder were prepared with various FRP wastes fine powder replacement(5∼30 wt%) for fine aggregate and polymer-cement ratios(5∼20 wt%). The water-cement ratio, water absorption rates and hot water immersion test, compressive and flexural strengths of polymer modified mortars were tested and the results compared to those of ordinary portland cement mortar. As the results, compressive and flexural strengths of polymer modified mortar containing FRP wastes fine powder depend on the contents of FRP wastes fine powder, type and additional amounts of polymer modifier. Some of them showed higher compressive and flexural strengths than those of ordinary portland cement mortar. Especially, SBR-modified mortar showed the highest strengths properties among three types of polymer modifier. Also water absorption rates, compressive and flexural strengths of SBR-modified mortar were more superior than those of PAE or EVA-modified mortar. The optimum mix proportions of SBR-modified mortar was 20 wt% of polymer-cement ratio and 20 wt% of FRP wastes fine powder replacement. Otherwise heat cured polymer modified mortar accelerated the improvement of early compressive and flexural strengths.

Improvement of Deformation Resistancy of Asphalt by Modification with Tire Rubber (타이어고무를 이용한 개질에 따른 아스팔트 변형저항성 향상 연구)

  • Hong, Young-Keun;Ko, Mun-Bo
    • Elastomers and Composites
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    • v.43 no.2
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    • pp.72-81
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    • 2008
  • Nowadays, modifying asphalt to improve the resistancy of plastic deformation or rutting on roads has been drawing attention. In this study, asphalts were modified with modifying agents and ground rubber from waste tire (GRT), and the effects of modifier and GRT on the properties of asphalt were analyzed. The Marshall stability of modified asphalt was increased by 98% and the tensile strength increased by 43% compared to straight asphalt. GRT played an important role in enhancing these properties. Viscosity tests, penetration tests and TMA analysis showed the deformation resistancy of modified asphalt. IR and GPC tests indicated that asphalt and modifier have similar chemical structures to each other, and chemical bonding between asphalt and modifier have occurred so that the molecular size lengthened.

Linear viscoelastic behavior of acrylonitrile-butadiene-styrene(ABS) polymers in the melt: Interpretation of data with a linear viscoelastic model of matrix/core-shell modifier polymer blends

  • Park, Joong-Hwan;Ryu, Jong-Hoon;Kim, Sang-Yong
    • Korea-Australia Rheology Journal
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    • v.12 no.2
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    • pp.135-141
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    • 2000
  • The linear viscoelastic behavior of acrylonitrile-butadiene-styrene (ABS) polymers with different rubber content has been investigated in the frame of a linear viscoelastic model, which takes into account the inter-connectivity of the dispersed rubber particles. The model developed in our previous work has been shown to properly predict the low frequency plateau for the storage modulus, which is generally observed in polymer blends containing core-shell-type impact modifiers. In the present study, further experiments have been carried out on ABS polymers with different rubber content to verify the validity of our linear viscoelastic model. It has been found that our model describes quite properly the rheological behavior of ABS polymers with different rubber content, especially at low frequencies. The experimental data confirm that our model describes the rheological properties of rubber-modified thermoplastic polymers with strong adhesion at the particle/matrix interface more accurately than the Palierne model.

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Preparation of PDMS Surface Modifier Using Silane-Functionalized Polymer Precursor Manufacture and Their Properties (실란 기능화 아크릴 고분자 전구체를 이용한 PDMS 표면 개질제 제조 및 표면 물성)

  • Shin, Jae-Hyeon;Kim, Nahae;Kim, Juyoung
    • Journal of Adhesion and Interface
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    • v.19 no.4
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    • pp.154-162
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    • 2018
  • Plasma treatment and corona treatment have been used for surface modification of polydimethylsiloxane (PDMS) film by activating its surface with the -OH group. Adhesion promoter or coupling agent was also used to improve adhesion of PDMS film with various materials. However, obtained hydrophilicity onto the surface of PDMS films with those processes was transient and vulnerable. In this study, a new alkoxysilane-functionalized acrylic polymer precursor was first synthesized by copolymerization process, and then was reacted with HO-terminated PDMS through condensation reaction to prepare a new surface modifier for PDMS film. The structure and molecular weight of the prepared surface modifier were confirmed by 1H-NMR and GPC measurement. Surface properties of surface modifier-coated PDMS films were also investigated by using XPS, ATR and WCA analysis. The adhesion between the PDMS film and the surface modifier was tested using cross-cut test.

Computer Simulation of the Effects of Content and Dispersion of Impact Modifier on the Impact Strength of Nylon 6 Composites (충격보강제의 함유량과 분산이 나일론 6 복합체의 충격강도에 미치는 영향의 컴퓨터 해석)

  • Woo, Jeong Woo;Lyu, Min-Young
    • Elastomers and Composites
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    • v.49 no.4
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    • pp.284-292
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    • 2014
  • Polymer has low mechanical strength than metal. In particular, the impact strength is very weak. Impact modifier reinforced polymers are frequently used. Impact strength of reinforced polymer is changed according to content and distribution of impact modifier. In this study, izod impact test has been simulated to analyze the mechanism of impact modifier reinforced Nylon 6. Computational results were compared for numbers and distributions of impact modifier. As the total volume of rubber particles decreased, the stress at the notch increased for the simulation model that the volume decreases as particle number increases. As the surface area of particle sphere increased, the stress and difference of principle stress increased for the simulation model that the total surface increases as particle number increases.

Characteristics of EVA-Polymer Modified Mortars Recycling Rapid-chilled Steel Slag Fine Aggregate (급냉 제강슬래그를 재활용한 EVA-폴리머 시멘트 모르타르의 특성)

  • Hwang, Eui-Hwan;Kim, Jin-Man
    • Applied Chemistry for Engineering
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    • v.19 no.6
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    • pp.652-660
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    • 2008
  • For the recycling of rapid-chilled steel slag, the mechanical strengths and physical properties of EVA-polymer modified mortars with the various replacement ratios of rapid-chilled steel slag were investigated. Twenty five specimens of polymer modified mortars were prepared with the five different amounts of EVA-polymer modifier (0, 5, 10, 15, 20 wt%) and rapid-chilled steel slag (0, 25, 50, 75, 100 wt%). For the investigation of the characteristics of polymer modified mortars, the measurements such as water-cement ratio, unit volume weight, air content for fresh mortar and compressive strength, flexural strength, water absorption, hot water resistance, porosity and SEM investigation for curing specimens were conducted. As a results, with an increase in the replacement ratio of rapid-chilled steel slag, water-cement ratios decreased but unit volume weight increased remarkably. With increasing EVA-polymer modifier and the replacement ratio of rapid-chilled steel slag, percent of water absorption decreased but compressive and flexural strengths increased remarkably. By the hot water resistance test, mechanical strengths decreased but total pore volume and porosity increased remarkably. In the SEM observation, the components of specimen were shown to stick to each other in the form of co-matrix phase before hot water resistance test, but polymer modifier of co-matrix phase was decomposed or deteriorated after hot water resistance test.