• Title/Summary/Keyword: Resin complex

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Desorption Characteristics for Previously Adsorbed Gold and Copper-Cyanide Complexes onto Dowex21K XLT Resin Using Mixed Solvent with HCl and Acetone (염산과 아세톤의 혼합용매를 이용한 Dowex21K XLT 수지에 흡착된 금과 구리-시안 착화합물의 탈착 특성)

  • Jeon, Choong
    • Clean Technology
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    • v.19 no.4
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    • pp.487-491
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    • 2013
  • To efficiently desorb gold and copper-cyanide complexes adsorbed onto Dowex21K XLT resin, the mixed solvent with HCl and acetone which is a kind of dipolar aprotic solvent was used as a desorbing agent. The desorption efficiency for gold-cyanide complex was the highest as about 94% when the mixing ratio of HCl and acetone based on volume was the 7:3, however, the value decreased as the ratio of acetone increased. In the case of copper-cyanide complex, most of them was desorbed when the amount of HCl was relatively higher than that of acetone, however, desorption efficiency decreased as the ratio of acetone increased. The desorption efficiency for gold and copper-cyanide complexes was the 94 and 100%, respectively at the 0.6 M of HCl with the 7 (HCl) : 3 (Acetone) of mixing ratio and desorption efficiency for gold-cyanide complex not increased any more even though higher HCl concentration was used. And the desorption efficiency for gold and copper-cyanide complexes was about 100% at the S/L raio ${\leq_-}1.0$ whereas desorption efficiency for gold-cyanide complex was very low as about 20-29% at the S/L ratio > 1.0. Also, most of desorption process for gold and copper-cyanide complexes was completed within 120 min.

Elution Behaviors of Stannous Ion by PSA on Chelating Resin (킬레이트 수지에서의 PSA에 의한 주석(Ⅱ)이온의 용리현상)

  • Cha, Ki-Won;Choi, Hyun-Cheol
    • Journal of the Korean Chemical Society
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    • v.39 no.5
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    • pp.379-383
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    • 1995
  • The elution behaviors of stannous ion by PSA(phenol sulfonic acid) as an eluent on chelating resin, Amberlite IRC-718 have been investigated. When 0.10 M stannous solution was adsorbed on the resin and eluted with various concentrations of PSA, the two peaks of stannous ion were appeared in the elution curve. These two peak areas were changed according to the PSA concentration. Using these results, the stability constant of the complex formation between Sn2+ and PSA was calculated. This value is 2.0 ${\times}$ 10-1.

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A Study on the Manufacturing of Screw Rotors for Air-Compressors Using RTM Process (Resin Transfer Molding을 이용한 공기 압축기용 스크류로터 제작에 관한 연구)

  • 서정도;이대길
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.139-142
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    • 1999
  • Screw rotors are core parts of screw type air compressors, compressors in refrigerating machines and super chargers of automobiles etc. They are composed of a female and a male rotors which have complex section profiles and helically swept geometry. Screw type compressors have advantages of low noise, high efficiency, less needs in maintenance etc. Usually, machining process of screw rotors requires long machining time using CNC machine designed only for screw rotors, which increase the cost of production. In this work, the screw rotors for air-compressors were manufactured with fiber reinforced epoxy composite materials by resin transfer molding process. The mold for the RTM process was made of aluminum and silicon rubber and was designed for release of helical shape products. Composite screw rotors, manufactured by RTM process, have advantages of lightweight, less cost of production, good characteristics of vibration etc.

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Curing characteristics of the Photocurable Resin for Fabrication of Micro-structures with overhang shape (돌출 형상을 가진 마이크로 구조물 가공을 위한 광경화성 수지의 경화 특성)

  • Jeoung M.G.;Choi J.W.;Ha Y.M.;Lee S.H.;Kim H.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.491-492
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    • 2006
  • In the microstereolithography which can make 3-D microstructures, curing depth is different according to exposure energy. Curing depth has to be controlled to fabricate complex 3-D microstructures with overhang shape. It becomes increases when the exposure energy increases. And photocurable resin is cured when the exposure energy is bigger than critical energy. So optimal exposure energy has to be found to fabricate overhang structures without being gel. To make thinner layer, UV absorber is used and exposure pattern is changed. In this paper, we find curing characteristics according to exposure energy, and fabricate microstructures with overhang shape.

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감성물질의 마이크로캡슐화에 의한 감성기능 섬유의 개발(IV) -감온변색 기능섬유-

  • 김문식;박수민
    • Textile Coloration and Finishing
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    • v.9 no.6
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    • pp.79-86
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    • 1997
  • The microcapsule for thermochromism is based on the polymerization reaction between epoxy resin and amine curing agent. The preparation process of microcapsule is based on dissolving or dispersing a hydrophobic core materials[one-dye-black(OBD), bis-phenol A(BPA), cetyl alcohol] in an aqueous solution of gelatin, epoxy resin and isophorondiamine(IPDA) ; the gelatin and IPDA used as a dispersion stabilizer and an hardening agent, respectively. The structures of epoxy resin and microcapsule materials have been analyzed by FT-IR and UV/Vis spectra. The mean diameter and size distribution of microcapsule are 1.46~1.75${\mu}{\textrm}{m}$ and 1.42, respectively. The DSC thermograms of microcapsules indicated 2 kinds of endothermic peaks at 47 and 322$^{\circ}C$. This is possibly corresponding to the melting peak of core material and wall meterial. These microcapsules are applied to the fabric by printing. Complex finished fabric showed a good wear resistance on rubbing test and the print pattern to the cotton fabric showed a reversible thermochromism ; ${\mu}_{max}$ are 580 nm below 4$0^{\circ}C$ and 276.5nm above 4$0^{\circ}C$ in ethanol/water(2/8), respectively.

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Resin bonding of metal brackets to glazed zirconia with a porcelain primer

  • Lee, Jung-Hwan;Lee, Milim;Kim, Kyoung-Nam;Hwang, Chung-Ju
    • The korean journal of orthodontics
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    • v.45 no.6
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    • pp.299-307
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    • 2015
  • Objective: The aims of this study were to compare the shear bond strength between orthodontic metal brackets and glazed zirconia using different types of primer before applying resin cement and to determine which primer was more effective. Methods: Zirconia blocks were milled and embedded in acrylic resin and randomly assigned to one of four groups: nonglazed zirconia with sandblasting and zirconia primer (NZ); glazed zirconia with sandblasting, etching, and zirconia primer (GZ); glazed zirconia with sandblasting, etching, and porcelain primer (GP); and glazed zirconia with sandblasting, etching, zirconia primer, and porcelain primer (GZP). A stainless steel metal bracket was bonded to each target surface with resin cement, and all specimens underwent thermal cycling. The shear bond strength of the specimens was measured by a universal testing machine. A scanning electron microscope, three-dimensional optical surface-profiler, and stereoscopic microscope were used to image the zirconia surfaces. The data were analyzed with one-way analyses of variance and the Fisher exact test. Results: Group GZ showed significantly lower shear bond strength than did the other groups. No statistically significant differences were found among groups NZ, GP, and GZP. All specimens in group GZ showed adhesive failure between the zirconia and resin cement. In groups NZ and GP, bonding failed at the interface between the resin cement and bracket base or showed complex adhesive and cohesive failure. Conclusions: Porcelain primer is the more appropriate choice for bonding a metal bracket to the surface of a full-contour glazed zirconia crown with resin cement.

Three-Dimensional Mold Filling Simulation for Multi-layered Preform in Resin Transfer Molding (다층 예비성형체에 대한 삼차원 충진해석)

  • Yang, Mei;Song, Young-Seok;Youn, Jae-Roun
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.04a
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    • pp.137-140
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    • 2005
  • Resin transfer molding (RTM) is one of the most popular processes for producing fiber reinforced polymer composites. In the manufacture of complex thick composite structures, analysis on flow front advancement on the resin impregnating the multi-layered fiber preform is helpful for the optimization of the process. In this study, three-dimensional mold filling simulation of RTM is carried out by using CVFEM (Control Volume Finite Element Method). On the assumption of isothermal flow of Newtonian fluid, Darcy’s law and continuity equation are used as governing equations. Different permeability tensors employed in each layer are obtained by experiments. Numerically predicted flow front is compared with experimental one in order to validate the numerical results. Flow simulations are conducted in the two mold geometries, rectangular plate and hollow cylinder. Permeability tensor of each layer preform in Cartesian coordinate system is transformed to cylinder coordinates system so that the flow within the multi-layered preforms of the hollow cylinder can be calculated exactly. Our emphasis is on the three dimensional flow analysis for circular three-dimensional braided preform, which shows outstanding mechanical properties such as high impact strength and toughness compared with other conventional two-dimensional laminar-structured preforms.

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Mechanical Properties of Radiation-Curing Vinyl Ester Resin (방사선 경화 비닐에스터 수지의 기계적 특성 연구)

  • Shin, Bum-Sik;Jeun, Joon-Pyo;Kim, Hyun Bin;Kang, Phil-Hyun
    • Journal of Radiation Industry
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    • v.4 no.1
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    • pp.19-23
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    • 2010
  • Vinyl ester (VE) resins, introduced in the late 1960s, have made large strides in reinforced plastics applications as adhesive and matrix materials on their appropriate mechanical performance characteristics in the glassy state. Generally, VE resins are a group of dimethacrylate resins based on bisphenol A type epoxy resin. They exhibit easy handling properties as well as good resistance to most chemical agents due to their mechanical and thermal properties. In this study, the effects of curing methods of vinyl ester resins on gel contents, flexural strength and dynamic mechanical properties were investigated. Thermal curing (room temperature, $80^{\circ}C$) and electron beam curing were used to crosslink a VE resin/styrene complex (65/35 wt%) with methyl ethyl ketone peroxide (MEKPO) as a catalyst and an 8 wt% cobalt naphthenate in styrene solution as a accelerator. For the samples, gel contents as well as flexural strength and dynamic mechanical properties were characterized and compared by soxhlet apparatus, universal testing machine (UTM) and dynamic mechanical analysis (DMA). As a result, the electron-cured VE resin was confirmed as a better condition than those for gel contents, flexural strength and dynamic mechanical properties, respectively.

RHEOLOGICAL PROPERTIES OF RESIN COMPOSITES ACCORDING TO THE CHANGE OF MONOMER AND FILLER COMPOSITIONS (단량체 및 무기질 filler 조성 변화에 따른 복합레진의 유변학적 특성)

  • Lee In-Bog;Lee Jong-Hyuck;Cho Byung-Hoon;Son Ho-Hyun;Lee Sang-Tag;Um Chung-Moon
    • Restorative Dentistry and Endodontics
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    • v.29 no.6
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    • pp.520-531
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    • 2004
  • The aim of this study was to investigate the effect of monomer and filler compositions on the rheological properties related to the handling characteristics of resin composites. Methods. Resin matrices that Bis-GMA as base monomer was blended with TEGDMA as diluent at various ratio were mixed with the Barium glass (0.7 um and 1.0 um), 0.04 um fumed silica and 0.5 um round silica. All used fillers were silane treated. In order to vary the viscosity of experimental composites, the type and content of incorporated fillers were changed, Using a rheometer, a steady shear test and a dynamic oscillatory shear test were used to evaluate the viscosity ($\eta$) of resin matrix, and the storage shear modulus (G'), the loss shear modulus (G"), the loss tangent ($tan{\delta}$) and the complex viscosity (${\eta}^*$) ofthe composites as a function of frequency ${\omega}{\;}={\;}0.1-100{\;}rad/s$. To investigate the effect of temperature on the viscosity of composites, a temperature sweep test was also undertaken. Results. Resin matrices were Newtonian fluid regardless of diluent concentration and all experimental composites exhibited pseudoplastic behavior with increasing shear rate. The viscosity of composites was exponentially increased with increasing filler volume%. In the same filler volume, the smaller the fillers were used, the higher the viscosities were. The effect of filler size on the viscosity was increased with increasing filler content. Increasing filler content reduced $tan{\delta}$ by increasing the G' further than the G". The viscosity of composites was decreased exponentially with increasing temperature.

ENHANCED MICROWAVE ABSORPTION OF CNT COMPOSITES MIXING WITH Fe3O4 AND CARBONYL IRON

  • JUNG HYO PARK;JAEHO CHOI;KISU LEE;JINWOO PARK;JUNG KUN SONG;EUNKYUNG JEON
    • Archives of Metallurgy and Materials
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    • v.63 no.3
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    • pp.1513-1516
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    • 2018
  • We fabricated two different kinds of composite materials for absorbing microwave in a frequency range of 2 to 18 GHz using coaxial airline and thru-reflect-line (TRL) method. The composite materials having carbon nanotube (CNT) with carbonyl iron (CI) or iron oxide (Fe3O4) were fabricated by mixing each components. Magnetic properties were measured by SQUID equipment. Complex permittivity and complex permeability were also obtained by measuring S-parameters of the toroidal specimen dispersing CI/CNT and Fe3O4/CNT into the 50 weight percent (wt%) epoxy resin. The real permittivity was improved by mixing the CNT however, the real permeability was same as pure magnetic powders. The CI/CNT had a maximum value of real permittivity and real permeability, 11 and 1.4 at 10 GHz, respectively. The CNT composites can be adapted to the radar absorbing materials, band width 8-12 GHz.