• Title, Summary, Keyword: epoxy viscosity

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Rheological behavior during the phase separation of thermoset epoxy/thermoplastic polymer blends

  • Kim, Hongkyeong;Kookheon Char
    • Korea-Australia Rheology Journal
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    • v.12 no.1
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    • pp.77-81
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    • 2000
  • Rheological behavior of thermoset/thermoplastic blends of epoxy/polyethersulphone (PES) was monitored during curing of the epoxy resin. During the isothermal curing of the mixture, a fluctuation in viscosity just before the abrupt viscosity increase was observed. This fluctuation is found to be due to the phase separation of PES from the matrix epoxy resin during the curing. The experimentally observed viscosity fluctuation is simulated with a simple two phase suspension model in terms of the increase in domain size. The viscosity profiles obtained experimentally at different isothermal curing temperatures are in good agreement with the predictions from the simple model taking into account the viscosity change due to the growth of PES domain and the network formation of the epoxy matrix.

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Properties of Epoxy Modified PVC-sol Sealants (에폭시가 함유된 PVC졸 실란트의 물성)

  • Lee, Seung-Jin;Kim, Hyun-Kyo;Park, Hwan-Man;Cho, Won-Jei;Ha, Chang-Sik
    • Elastomers and Composites
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    • v.34 no.3
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    • pp.199-211
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    • 1999
  • In this work, the effects of the addition of epoxy on the properties of PVC-sol sealants were investigated. PVC-sol was plasticized with dioctyl phthalates(DOP). Two kinds of epoxy resins having different epoxy equivalent weight (E.E.W.) were used. It was found that the properties of the PVC-sol sealants were significantly affected by the contents and types of the added epoxy resins. The viscosity behaviors of the epoxy-modified sealants, in the case of epoxy A addition, the viscosity was decreased with increasing the epoxy contents, but In the case of $CaCO_3$ addition, the viscosity was increased with increasing the $CaCO_3$ contents. The viscosity of epoxy modified sealants aged at $45^{\circ}C$ waterbath was decreased with increasing epoxy contents, since the epoxy acted on the sealants as a stabilizer. The thermal stability of the PVC-sol sealants was slightly improved by adding epoxy. The tensile strength and elongation of sealants modified with epoxy A(two functionalities of epoxy) were increased with increasing the epoxy contents up to a certain epoxy contents but was decreased with further increasing the epoxy contents. In the case of $CaCO_3$ addition, the tensile strength of sealants were decreased with increasing the $CaCO_3$ contents. In view of the electrical properties, such as tan ${\delta}$($0.1{\pm}0.04$) and ${\epsilon}_r$($0.5{\pm}0.04$), it was found that the epoxy modified sealants were as good as insulators.

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Study on the Peel off Style Low Viscosity Epoxy and Separation Media for a Moving Historic Sites (유구 이전 전용 저점도형 에폭시와 박리제에 관한 연구)

  • Han, Won-Sik;Hong, Tae-Kee;Park, Gi-Jung;Lim, Sung-Jin;Wi, Koang-Chul
    • Journal of Conservation Science
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    • v.24
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    • pp.37-42
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    • 2008
  • Stability of the moving historic sites have something to do with the degree of easiness of work as well as physical property of polymer product. These agents should be able to use without the effect of outer environments like water or low temperature and must have stability during progress of working the peel off Urethane pre-product from Epoxy surface. So, we synthesized low viscosity epoxy resin and hardener with best physical quality and separation media for the moving of historical sites. These products have very good tension strength, adhesion strength, low viscosity and various physical properties that the users want. Particularly, separation media products have good separation of Urethane pre-products surface and Epoxy final product surface.

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A Study on the Viscous Properties of Polyvinyl Acetate Emulsion Mixed with SBR, Polyurethane and Epoxy Latex (SBR, 폴리우레탄 및 에폭시 라텍스를 혼합한 폴리초산비닐 에멀젼 수지의 점성에 관한 연구)

  • Choi, Sang-Goo;Suh, Won-Dong;Park, In-Suk
    • Elastomers and Composites
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    • v.33 no.2
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    • pp.83-92
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    • 1998
  • SBR latex, polyurethane latex and epoxy latex were mixed with polyvinyl acetate emulsion in 0~15% (wt.%). For the mixtures, the viscous properties were examined. The viscosity was influenced by the dispersed phase and the chain structures of polymer, and decreased with the rising of temperatures. The viscosity was increased with mixing of epoxy latex, but decreased with addition of SBR latex or polyurethane latex. Thixotropic index was influenced on the size of micelle and hydrogen bond. The thixotropic index was increased with mixing of epoxy latex or polyurethane latex within 5%, but keep up equality over that. The thixotropic index was decreased with mixing of SBR latex within 5%, but keep up equality over that. The relative viscosity were influenced on the activity of molecule and the interference of dispersed phases, was increased with the rising of temperatures. The relative viscosity was decreased with mixing of epoxy latex, but increased with mixing of SBR latex or polyurethane latex.

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Prediction of Viscosity in Liquid Epoxy Resin Mixed with Micro/Nano Hybrid Silica (액상 에폭시 수지와 마이크로/나노 하이브리드 실리카 혼합물의 점도 예측)

  • Huang, Guang-Chun;Lee, Chung-Hee;Lee, Jong-Keun
    • Korean Journal of Materials Research
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    • v.21 no.2
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    • pp.100-105
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    • 2011
  • The relative viscosity was measured at different filler loadings for a cycloaliphatic epoxy resin and hexahydro-4-methylphthalic anhydride hardener system filled with micro/nano hybrid silica. Various empirical models were fitted to the experimental data and a fitting parameter such as critical filler fractions (${\phi}_{max}$) was estimated. Among the models, the Zhang-Evans model gave the best fit to the viscosity data. For all the silica loadings used, ln (relative viscosity) varied linearly with filler loadings. Using the Zhang-Evans model and the linearity characteristics of the viscosity change, simple methods to predict the relative viscosity below ${\phi}_{max}$ are presented in this work. The predicted viscosity values from the two methods at hybrid silica fractions of $\phi$ = 0.086 and 0.1506 were confirmed for a micro:nano = 1:1 hybrid filler. As a result, the difference between measured and predicted values was less than 11%, indicating that the proposed predicting methods are in good agreement with the experiment.

Study on the Compatibility of Brominated Epoxy Resin with Nylon 6 and the Characterization of the Blends (브롬화 에폭시 수지와 나일론 6의 상용성 및 블렌드 수지의 물성에 관한 연구)

  • Kim, Hwan-Chul
    • Textile Coloration and Finishing
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    • v.22 no.2
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    • pp.155-162
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    • 2010
  • Nylon 6 was blended with a brominated epoxy resin, tetrabromobisphenol A diglycidyl ether (DGEBBA), to enhance flame retardant property. Thermal properties of the blends were analyzed by DSC. Melting point and crystallization temperature decreased as the amount of epoxy resin increased. Melt index and relative viscosity decreased as the amount of the epoxy resin increased. When the blended amount of the epoxy resin was below 5%, the melt index decreased while the relative viscosity slightly increased. The blend resin was successfully spun into fiber without swelling or drawing the resonance phenomena. However, both the tenacity and elongation of the fiber decreased by increasing the amount of the DGEBBA.

A Study on the Properties of Ethylene-Vinyl Acetate Emulsion Blended with SBR, Urethane and Epoxy Latex (에폭시, 우레탄 및 SBR계 라텍스를 혼합한 에틸렌-비닐아세테이트 에멀젼의 특성에 관한 연구)

  • Choi, Sang-Goo
    • Elastomers and Composites
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    • v.34 no.5
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    • pp.414-422
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    • 1999
  • SBR, polyurethane and epoxy latex were separately blended with ethylene-vinyl acetate(EVA) emulsion In $0{\sim}50%$. EVA emulsion was not reacted with latexes in liquid phase and mixtures had good stroage stability. The viscosity of cement mixtures was elevated to 20,000cps in $0.5{\sim}2.0$ hours by mixing. The mixtures mixed with pigment represented high viscosity and showed higher viscosity as time goes by. Mixtures had higher hardness with mixing SBR than mixing epoxy or urethane. The hardness was suddenly increased over cement content 30%. showed pencil hardness $H{\sim}2H$ in $50{\sim}60%$. The increase of hardness in high solids was depended upon not only the condensation of latexs but also the coagulation and adhesion of cement particle.

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Synthesis and Characterization of Low Viscosity Aromatic Hyperbranched Polyester Epoxy Resin

  • Zhang, Daohong;Jia, Demin;Zhou, Zihu
    • Macromolecular Research
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    • v.17 no.5
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    • pp.289-295
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    • 2009
  • Low viscosity aromatic hyperbranched polyester epoxy resin (HTBE) was synthesized by the reaction between epichlorohydrin (ECH) and carboxyl-end hyperbranched polyester (HTB) which was prepared from inexpensive materials $A_2$ (1,4-butanediol glycol, BEG) and $B_3$ (trimellitic anhydride, TMA) by pseudo one-step method. The molar mass of the HTB was calculated from its acid value by "Recursive Probability Approach". The degree of branching (DB) of the HTB was characterized by model compounds and $^1H$ NMR-minus spectrum technology, and the DB of the HTB was about $0.47{\sim}0.63$. The viscosity and epoxy equivalent weight of the HTBE were $3,600{\sim}5,000\;cp$ and lower than 540 g/mol respectively. The reaction mechanism and structure of the $AB_2$ monomer, HTB and HTBE were investigated by MS, $^1H$ NMR and FTIR spectra technology. The molecular size of HTBE is under 8.65 nm and its shape is ellipsoid-like as determined by molecular simulation.

An Experimental Study on the Characteristics of Deformation of Repaired Epoxy Resin by Flexural Strength Test (휨시험에 의한 에폭시 균열주입제의 변형특성에 관한 실험적 연구)

  • Kim Jae Sung;Bae Jun Young;Kim Kyung Deok;Kang Suk Pyo;Kawk Ju Ho;Kim Jung Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.269-272
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    • 2005
  • Epoxy resins are gradually becoming some of the most important and versatile polymers in modem civil engineering. Because epoxy resins have some unigue properties, such as toughness, versatility of viscosity and curing conditions, good handling characteristics, high adhesive strength, inertness, low shrinkage compared to most other thermo-setting resins and concrete, and resistance to chemicals, they have found many applications in construction castings, repair materials, road or bridge deck pavements, coatings, and as structural or non structural adhesives. In this applications, epoxy resins are widely used for polymer concretes, grouting materials, injection glues, and sealants. In this paper, characteristics of deformation of repair material after repaired have been investigated by viscosity of repair material and the width of crack. It is believed that flexural strength of epoxy resin with low viscosity is high because tensile strength is high and elongation at break is low, fracture energy is low.

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Case Study of Flexural Strength Evaluation of Epoxy Injected Concrete Using Low Pressure Mixed with Mechanical High Pressure (기계식 고압과 저압을 혼용한 에폭시 주입 콘크리트의 휨강도 검토 사례 연구)

  • Hong, Ki-Nam;Yu, Yeon-Jong;Lee, Kang-Moon;Ryu, Chang-Yeol;Yoon, Hong-Su
    • Journal of the Korean Society of Safety
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    • v.27 no.1
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    • pp.49-54
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    • 2012
  • The objective of this study is to investigate the capacity of epoxy injection method using low pressure mixed with high pressure. Injection depth test and flexural strength test were respectively performed on $40{\times}45{\times}35$ cm and $100{\times}10{\times}40$ cm specimens. Considered as the test variables were injection type(low pressure, low and high pressure), crack width(0.25 mm, 0.50 mm), injection direction(upper, lower, side), and epoxy viscosity(low, medium, high). Test results showed that low viscosity epoxy injection depth of injector using low pressure mixed with high pressure for upper direction were 23 cm and tension strength of crack face repaired by injector using low pressure mixed with high pressure was larger than that of concrete.