• 제목/요약/키워드: filler dispersion

검색결과 109건 처리시간 0.024초

Effect of Carbon-based Nanofillers on the Toughening Behavior of Epoxy Resin

  • Lee, Gi-Bbeum;Kim, Haeran;Shin, Wonjae;Jeon, Jinseok;Park, In-Seok;Nah, Changwoon
    • Elastomers and Composites
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    • 제56권3호
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    • pp.179-186
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    • 2021
  • Carbon-based nanofillers, including nanodiamond (ND) and carbon nanotubes (CNTs), have been employed in epoxy matrixes for improving the toughness, using the tow prepreg method, of epoxy compounds for high pressure tanks. The reinforcing performance was compared with those of commercially available toughening fillers, including carboxyl-terminated butadiene acrylonitrile (CTBN) and block copolymers, such as poly(methyl methacrylate)-b-poly(butyl acrylate)-b-poly(methyl methacrylate) (BA-b-MMA). CTNB improved the mechanical performance at a relatively high filler loading of ~5 phr. Nanosized BA-b-MMA showed improved performance at a lower filler loading of ~2 phr. However, the mechanical properties deteriorated at a higher loading of ~5 phr because of the formation of larger aggregates. ND showed no significant improvement in mechanical properties because of aggregate formation. In contrast, surface-treated ND with epoxidized hydroxyl-terminated polybutadiene considerably improved the mechanical properties, notably the impact strength, because of more uniform dispersion of particles in the epoxy matrix. CNTs noticeably improved the flexural strength and impact strength at a filler loading of 0.5 phr. However, the improvements were lost with further addition of fillers because of CNT aggregation.

고분자 나노복합재료의 가공조건 및 물성 최적화 (Optimization of Processing Conditions and Mechanical Properties in Polymer Nanocomposite)

  • 남병욱;홍채환;황태원
    • 한국자동차공학회논문집
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    • 제15권6호
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    • pp.73-80
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    • 2007
  • Nanocomposites are used as a new class of polymer system and many researchers have been interested in the clay nanocomposite because of its good mechanical properties, heat resistance, flame retardancy, and barrier property. Modified layered silicates as fillers are dispersed at a nanometer-level within a polymer matrix and then new extraordinary properties are observed. In this study, polypropylene/clay nanocomposites were prepared in a twin screw extruder by the melt compounding method. In order to increase the compatibility of PP with the clay, the MAPP was used as a compatibilizer. And organic modified clays were used as a nanometric filler during the melt extrusion. Through the analysis of SAXS, WAXS, the dispersion of clay was investigated. These nanocomposites compared with a neat polypropylene/talc composite have high modulus, low toughness, and reduced shrinkage at the stable dispersion.

에폭시 복합체의 주파수 변화에 따른 유전특성 (Dielectric Properties of Epoxy Composites with Varying Frequency)

  • 이호식
    • 한국응용과학기술학회지
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    • 제35권3호
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    • pp.676-682
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    • 2018
  • 주파수 변화에 따른 에폭시 복합체의 전기적 특성을 알아보기 위하여 온도 범위 $20[^{\circ}C]$, $100[^{\circ}C]$, $140[^{\circ}C]$, 주파수 범위 30[Hz]~3[MHz] 사에서 유전율 및 유전손실을 측정하였다. 저주파 영역에서 유전분산과 유전 손실이 나타나고 있음을 확인하였다. 또한 고온 영역에서는 충진제의 영향으로 유전율이 감소하는 것을 확인하였다.

An empirical study on the X-ray attenuation capability of n-WO3/n-Bi2O3/PVA with added starch

  • Oliver, Namuwonge;Ramli, Ramzun Maizan;Azman, Nurul Zahirah Noor
    • Nuclear Engineering and Technology
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    • 제54권9호
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    • pp.3459-3469
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    • 2022
  • Matrix composites of n-WO3/n-Bi2O3/PVA with different loadings of n-WO3/n-Bi2O3 mixtures (0-15 wt%) and starch (0 and 3 wt%) were fabricated by using melt-mixing method. The X-ray attenuation capability were evaluated based on mass attenuation coefficient (μ/⍴) using a general diagnostic X-ray machine at 40-100 kVp. The effect of starch addition on the dispersion of the fillers in the PVA matrix were observed by using FESEM through morphological analysis. The fabricated samples have shrunken and caused their thickness to be decreased (0.35 mm-0.55 mm) after the drying process even though fixed thickness (2.0 mm) was set initially. The density and HVL values of the samples with 3 wt% starch was seen lower than samples without starch (0 wt%), however the former have provided improvement in filler dispersion and better X-ray attenuation capability compared to the latter. As conclusion, the matrix composite of n-WO3/n-Bi2O3/PVA with 15 wt% of n-Bi2O3, 8 wt% of n-WO3 and 3 wt% starch can be selected as the best promising candidate for X-ray shielding materials.

에폭시 복합재료의 강화에 사용된 탄소나노튜브의 분산 개선에 미친 전단혼합의 영향 (Effects of Shear Mixing on the Dispersion Improvement of Carbon Nanotube Fillers in Epoxy Composites)

  • 구민예;이교우
    • 한국산학기술학회논문지
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    • 제13권10호
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    • pp.4385-4391
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    • 2012
  • 본 연구는 전단혼합과 초음파 처리를 통해 충전재의 분산을 증대시켜 복합재료 시편을 만들고, 분산의 적정성을 판단하기 위해서 주사전자현미경 이미지를 이용하며, 인장실험을 통해 기계적 물성치를 측정하고 고찰하였다. 초음파 처리와 전단혼합 시간 증가를 통해서 개선된 공정으로 만들어진 시편의 경우, 충전재 분산에 대한 정성적인 평가인 SEM 이미지와 정량적인 평가인 인장시험 데이터의 상호 보완을 통해 충전재의 복합재료 수지 내에서의 적절한 분산 여부를 판단할 수 있었다. 인장강도의 측정 결과에서는 충전재가 함유된 모든 시편이 Pure Epoxy 시편 보다 높은 인장 강도를 보였는데, 충전재 0.6wt%에서 가장 높은 인장강도 값을 나타냈다. 0.9wt%와 1.2wt% 시편은 Pure Epoxy 시편보다는 인장강도가 증가하였지만 0.6wt% 시편보다 작은 값을 보였다. 인장강성 측정 결과는 충전재의 함유량이 높아질수록 증가하는 결과를 보였다.

Effect of Particle Size and Dispersion on Dielectric Properties in ZnO/Epoxy Resin Composites

  • Yang, Wenhu;Yi, Ran;Yang, Xu;Xu, Man;Hui, Sisi;Cao, Xiaolong
    • Transactions on Electrical and Electronic Materials
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    • 제13권3호
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    • pp.116-120
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    • 2012
  • In this paper, ZnO-Epoxy nanocomposites (NEP) were prepared and epoxy composites that contain 5 wt% micro ZnO (MEP) and deliberately not well dispersed nano ZnO (NDNEP) were also prepared for purpose of comparison. The effects of the particle size and dispersion of ZnO on dielectric properties of epoxy resin were chiefly studied. Test results showed that: at a loading of 5 wt%, the three epoxy composites seem to have no significant difference on resistivity compared to epoxy resin; Dielectric constants of all the epoxy composites are also basically the same but they are bigger compared to that of the pure epoxy resin (unfilled); Dielectric dissipation factors ($tan{\delta}$) of NDNEP is greater than that of NEP and MEP. NEP has the minimum dielectric loss factor, whereas dielectric loss factors of the three epoxy composites are larger than that of the pure epoxy resin. The decreasing order of electrical breakdown strength for the three epoxy composites and for the pure epoxy resin is as follows: NEP>MEP>NDNEP>EP. Finally, in order to explain the experimental results the aggregation interface phase was proposed. Furthermore, addition of well dispersed nano filler has proved to have a positive effect on the improvement of the dielectric properties of epoxy resin.

초음파 조사에 의한 복합재료의 계면특성의 보강 개선에 관한 연구 (II) (A Study to Improve the Interface Strength of Composite Materials by the Radiation of Ultrasonic Energy)

  • 이상국;전춘생;김익년
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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    • pp.179-182
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    • 1988
  • This study is to investigate the adhesive strength of composite material's interface on the experimental methode of tree growth in the material. The results are as fellows 1) The irradiations of ultrasonic energy cause the mechanical vibration in the polymer composite materials of fluid state, so then bring about physical dispersion and heat form inorganic materials, being supposed to produce chemical crosslinking reaction, decreasing of voids between filler and matrix. 2) The characterics of the breakdown are increased by using coupling agent in the composite material. 3) As the intensity of ultrasonic energy and its irradiated time are larger, the tree inception and break-down voltages increase and the tree growing is slower. so we obtain that the interface adhesive force tan be strengthened by the irradiation of ultrasonic energy.

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Influence of Kinds of Fatty Acids and Poly(ethylene glycol)s on Properties of Silica-Filled Natural Rubber Compounds

  • Park, Sung-Seen;Park, Sumgsoo
    • Macromolecular Research
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    • 제9권2호
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    • pp.92-99
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    • 2001
  • Silica-filled rubber compounds have slower cure characteristics than carbon black-filled ones due to the adsorption of curatives on the silica surface. Fatty acid was used as a cure activator along with zinc oxide in a sulfur cure system. Poly(ethylene glycol), PEG, was used in silica-filled rubber compounds to prevent adsorption of the curatives on the silica surface. In this study, influence of the size of fatty acid and PEG on properties of silica-filled NR compounds was investigated. It was found that the size of fatty acid and PEG affected the curt: characteristics and physical properties. The cure rate becomes faster as the PEG size increases. By increasing the size of fatty acid or PEG, the delta torque of the compound decreases while the Mooney viscosity increases. The modulus of the vulcanizate decreases with increasing the molecular weight of fatty acid or PEG. The experimental results were explained by the filler dispersion and by the prevention of the curative-adsorption on the silica surface.

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Enhanced Compatibility of PC/PMMA Alloys by Adding Multiwall Carbon Nanotubes

  • Bae, Do-Young;Lee, Heon-Sang
    • Carbon letters
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    • 제11권2호
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    • pp.83-89
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    • 2010
  • We prepared polycarbonate (PC)/poly(methyl methacrylate) (PMMA)/multiwall carbon nanotube (MWCNT) nanocomposites by co-rotating twin screw extruder at 533 K. Thermal analysis results indicate that the miscibility of PC and PMMA is enhanced by MWCNTs. Bead necklace-like morphology of PMMA-rich phase is observed in PC/PMMA/MWCNT nanocomposites with increasing PMMA weight fraction due to the bead necklace-like morphology. The tensile strength of PC/PMMA (75/25)/MWCNT (1 wt.%) nanocomposite is 3% higher than those of PC/PMMA (75/25) alloy. Suppression of die swell by MWCNT filler is observed in the melt flow of PC/PMMA/MWCNT nanocomposites during extrusion.

초음파 조사에 의한 복합재료의 계면특성의 보강 개선에 관한 연구(1) (A Study to Improve the Interface Strength of Composite Materials by the Radiation of Ultrasonic Energy (1))

  • 이상국;전춘생;김익년
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.813-816
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    • 1988
  • This study is to investigate the adhesive strength of composite material's interface on the experimental methode of tree growth in the material. The results are as follows 1) The irradiations of ultrasonic energy cause the mechanical vibration in the polymer composite materials of fluid state, so then bring about physical dispersion and heat for inorganic materials, being supposed to produce chemical interlinking reaction, decreasing of voids between filler and matrix. 2) As the intensity of ultrasonic energy and its irradiated time are larger, the tree inception and breakdown voltages increase and the tree growing is slower. so we obtain that the interface adhesive force can be strengthened by the irradiation of ultrasonic energy.

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