• Title/Summary/Keyword: Vulcanized Rubber

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Direct Analysis of Tackifying Resins in Vulcanized Rubber by Simultaneous Pyrosis Methylation-Gas Chromatography/Mass Spectrometry

  • 김승욱;허귀숙;이계호
    • Bulletin of the Korean Chemical Society
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    • v.19 no.2
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    • pp.164-169
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    • 1998
  • Vulcanized rubber containing three kinds of oligomeric resins such as cashew resin, t-octylphenol formaldehyde resin and terpene modified wood rosin has been characterized by simultaneous pyrolysis methylation-gas chromatography/mass spectrometry (SPM-GC/MS). After methylation by the SPM method using tetramethylammonium hydroxide, the methylated pyrolyzates of the corresponding resins were detected with higher sensitivity than underivatized pyrolyzates without any interferences from other ingredients of vulcanized rubber.

Effects of Maximum Strain and Aging Conditions on the Fatigue Life of Vulcanized Natural Rubber (가황 천연고무의 피로수명에 미치는 최대 변형률과 노화도 영향)

  • 우창수;김완두;김완수;권재도
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.4
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    • pp.181-190
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    • 2004
  • The interest of the fatigue life of rubber components such as engine mounts is increasing according to the extension of warranty period of the automotive components. Automotive engine mounts get damaged due to thermal and mechanical loadings. This paper discusses a fatigue life prediction of the 3-dimensional dumbbell specimens for natural rubber compound considering the effects of maximum strain and heat aging temperature. Displacement controlled fatigue life tests were performed using specimens with different levels of maximum strain and various hardness. The basic mechanical properties test and the fatigue test of aged rubber specimen under normal and elevated temperature were executed. A procedure to predicted the fatigue life of vulcanized natural rubber material based on the maximum strain method was proposed, and then this curve was in good agreement with fatigue test data less than 200% error range.

Surface treatment of vulcanized rubber by ArF excimer laser (ArF 엑시머 레이저에 의한 가류 고무의 표면처리)

  • Lee, Bong-Ju
    • Korean Journal of Optics and Photonics
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    • v.13 no.4
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    • pp.332-335
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    • 2002
  • Surface treatment was carried out by an Excimer Pulse laser beam in order to increase the adhesive strength of vulcanized rubber. With increasing number of laser beam irradiations, the adhesive strength was greatly increased; the adhesive strength was 1,500 N/m after irradiation 100 times. The energy density increase was in direct proportion to the adhesive strength increase; the maximum value of the adhesive strength was 1,500 N/m at the energy density of 176 mJ/$cm^{2}$. It was concluded that the increase of surface area was relevant to that of both energy density and adhesive strength

Improved Adhesive Strength of Vulcanized Rubber upon Laser Treatments

  • Sohn, Hong-lae;Lee, Bong-Ju
    • Macromolecular Research
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    • v.12 no.5
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    • pp.540-543
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    • 2004
  • Surface treatment using an excimer pulse laser beam has been conducted in order to increase the adhesive strength of vulcanized rubber. The adhesive strength increased with increasing the number of irradiation time with laser pulses and reached to 1,500 N/m after 100 cycles of irradiation. Increased in energy density was directly proportional to the improvement of the adhesive strength. Maximum value of the adhesive strength of 1,500 N/m obtained at the energy density of 176 mJ/$\textrm{cm}^2$. We conclude that an increased energy density improves in both the surface area and adhesive strength.

A study on the dielectric dispersion of vulcanized natural rubber (가황에 의한 천연고무의 유전분산에 관한연구)

  • Lee, Joon-Ung;Kim, Hak-Ju
    • Elastomers and Composites
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    • v.18 no.2
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    • pp.51-59
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    • 1983
  • The dielectric properties of polymers are very important when investigating the molecular structure of polymers. The characteristics of the dielectric absorption in vulcanized natural rubber were studied in frequency ranging from 10[KHz] to 32[MHz] at the temperature of 25[$^{\circ}C$]. As a result of the study, it has been confirmed that natural rubber vulcanized below 4phr leads to two kinds of dielectric losses due to the interfacial polarization and the dipole polarization by sulfur, and of above 7[%] was only a loss due to the dipole polarization by sulfur. Futhermore, the dielectric loss maximum $tan{\delta}$ spectrum, removed to the low frequency in accordance with increasing sulfur, depends greatly on sulfur. The volume resistivity of $10^{7}{\sim}10^{11}[{\Omega}{\cdot}cm}]$, regardless of whether the crosslinking of rubber is weakened by sulfur, was observed.

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Changes of Surface Properties by Plasma Treatment on the Surface of Semiconductive Silicone Rubber (반도전성 실리콘 고무의 플라즈마 처리에 따른 표면의 특성변화)

  • Lee, Ki-Taek;Huh, Chang-Su
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.8
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    • pp.696-701
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    • 2005
  • This paper was investigated the changes of surface properties of high-temperature-vulcanized (HTV) semiconductive silicone rubber due to oxygen plasma discharge. The modifications produced on the silicone rubber surface by oxygen plasma were accessed using Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), contact angle and Surface Roughness Tester. The results of the chemical analysis Showed that C-H bonds were broken due to plasma discharge and Silica-like bonds (SiOx, x=$3\~4$) increased. It is thought that the above changes lead to the increase of surface energy of high-temperature-vulcanized (HTV) semiconductive silicone rubber also, Surface roughness was increased with cleavage of side-chains and oxidation process, it confirmed change as the SEM. The micromorphology of surface and hydrophobicity due to plasma discharge based on our results were discussed.

An Experimental Study on the Physical Property of Non-Vulcanized Waterproofing Synthetic Rubber Sheet for the Underground Concrete Wall (지하 콘크리트 벽체용 미가황 합성고무시트 방수재의 물성에 관한 실험적 연구)

  • Choi, Eun Su;Lee, Dae Woo;Seo, Sang Kyo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.4
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    • pp.69-78
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    • 2012
  • This paper study on the physical property of naturally vulcanizing waterproofing synthetic rubber sheet for the underground concrete wall. In order to finding the naturally vulcanizing time, the relation of vulcanizing time and tensile strength is analysed from non-vulcanizing to naturally vulcanizing time. Physical tests such as tensile strength, tear strength: etc., under the thermal environment temperature at $-20^{\circ}C$, $-10^{\circ}C$, $20^{\circ}C$, $60^{\circ}C$. The result of experiment show that the developed rubber sheet has the delay time about 85 days and the curing time about 35 days. The tensile strength increased by about 692% and coefficient of expansion decreased by about 10% which value can be sufficiently compensate the demerit of vulcanized rubber sheet. Also, all of the physical properties of the naturally rubber sheet satisfy the KS standard and compare to the vulcanized rubber sheet, the developed naturally rubber sheet have excellent durability.

Preparation and Characterizations of Polymethylmethacrylate (PMMA)/Acrylate Rubber (ACM) Blend for Light Diffuser Applications

  • Lee, Byung Hwan;Chang, Young-Wook;Lim, Hyung Mi
    • Elastomers and Composites
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    • v.50 no.1
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    • pp.49-54
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    • 2015
  • Dynamically vulcanized PMMA/ACM (80 wt%/20 wt%) blend using DCP as a curing agent was prepared using internal mixer. The morphology, mechanical properties, optical properties, melt viscosity and die swell were characterized by using FE-SEM, tensile test, Izod impact test, dynamic mechanical analysis, ARES and capillary rheometer, respectively. The blends show a phase-separated morphology in which ACM are dispersed in PMMA matrix. Dynamically vulcanized blend exhibits higher mechanical properties, higher melt viscosity, and die swell as compared to simple blend. And, the dynamically vulcanized blend showed total transmittance of more than 75% and haze of higher than 90%, which enable it to find potential applications to fabricate an optical diffuser by extrusion process.

Influence of the Vulcanization on the Dielectric Properties of Natural Rubber (천연고무의 유전특성에 미치는 가황의 영향)

  • Lee, Joon-Ung;Yon, Dae-Heum
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.33 no.3
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    • pp.112-117
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    • 1984
  • The dielectric propertries of polymers are very important to investigate the molecular structure of polymer. The characteristrics of the dielectric absorption in vulcanized natural rubber were studied in the range of frequency from 10[KHz] to 32[MHz] at the temperature of 25[$^{\circ}C$]. As the results. it has been confirmed that in the case of natural ruber vulcanized between 2 and 4phr the specimens exhibit two kind of dielectric losses due to the dipole polarization by impurites and sulfure, and of above 7phr was only a loss due to the dipole polarization by sulfure and of natural rubber exhibit two kind of losses due to the interfacial and the dipole polarization. Furthermore, dielectric loss maximun tan spectrum, which removed to the low frequency according to increasing sulfure, depends greatly on sulfure. The volume resistivity of $10^{7}$~$10^{11}$[$\Omega\cdot$cm], regardness whether the crosslinking of rubber are tired by sulfure or, was observed.

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A Study of the Changes of Surface Properties on Semiconductive-Insulating of Silicone Rubber by Oxygen Plasma Treatment (산소 플라즈마 처리에 의한 반도전성 실리콘 고무 표면의 특성변화)

  • Lee, Ki-Taek;Hwang, Sun-Mook;Hong, Joo-Il;Huh, Chang-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05b
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    • pp.25-28
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    • 2005
  • This paper was investigated the changes of surface properties of high-temperature-vulcanized(HTV) semiconductive silicone rubber due to oxygen plasma discharge. The modifications produced on the silicone surface by oxygen plasma were accessed using x-ray photoelectron spectroscopy(XPS), contact angle and Scanning Electron Microscope(SEM). The results of the chemical analysis showed that C-H bonds were broken due to plasma discharge and Silica-like bonds (SiOx. x=3~4) increased. It is thought that the above changes lead to the increase of surface energy of high-temperature-vulcanized(HTV) semiconductive silicone rubber. The micromorphology of surface and hydrophobicity due to plasma discharge based on our results were discussed.

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