• Title/Summary/Keyword: polymer particle

Search Result 26, Processing Time 0.1 seconds

Development of Reflective Paper-like Display with Triboelectrically Charged-polymer Particles

  • Cho, Won-Ki;Kwon, Soon-Hyung;Lee, Sung-Guk;Kim, Nam-Jin;Ryu, Byung-Gil;Song, Moon-Bong
    • Journal of Information Display
    • /
    • v.6 no.3
    • /
    • pp.30-35
    • /
    • 2005
  • We have developed a paper-like display using polymer particles charged triboelectrically. By using a toner-type display with a simple structure, we continued that polymer particle movement is controlled by only a voltage difference between scan and data electrode. We fabricated a diagonal 2.4 inch panel on the glass substrate and successfully produced an image by the passive driving method with operating voltages of about ${\pm}$ 120 V. The contrast ratio was 4:1.

A Study on Dispersion Copolymerization of Styrene/n-Butylmethacrylate and Alumina (스티렌/노말 부틸 메타크릴레이트와 알루미나의 분산 공중합에 관한 연구)

  • Bang, Hyun-Su;Cho, Ur-Ryong
    • Polymer(Korea)
    • /
    • v.32 no.6
    • /
    • pp.549-554
    • /
    • 2008
  • In order to synthesize polymer particle containing inorganic material, styrene and n-butylmethacrylate were copolymerized with alumina by dispersion polymerization. The weight ratio of styrene to n-butylmethacrylate was 3 : 1. A poly(N-vinyl pyrrolidon) was added as stabilizer. 2,2'-AzobisCisobutyronitrile) and 3-methacryloxypropyl trimethoxysilane were used as initiator and coupling agent, respectively. The weight ratio of 70 : 30 of isopropanol to distilled water was used as dispersion medium. According to the TEM measurement, we could confirm that alumina was dispersed into the polymer particle. The increase 'of concentration of alumina resulted in enhancement of particle size, but decreased its distribution. By the XRD method, it was found that the increase of alumina concentration showed the increase of intensity in peak and the increased 2$\theta$ value. From the TGA measurement, the increase of alumina concentration caused high heat resistance of the polymer. With respect to the type of initiator, the longer half life of initiator, the smaller particle size. We also found that the increase of particle stabilizer concentration made the decreased of particle size due to the accelerated generation of polymer particle in the early stage of reaction.

Synthesis of Monodispersed Magnetic Polymer Particle (균일한 자성 고분자 입자의 합성)

  • Ahn, Byung Hyun
    • Applied Chemistry for Engineering
    • /
    • v.19 no.3
    • /
    • pp.316-321
    • /
    • 2008
  • Monodispersed particles of poly(styrene-co-4-vinylpyridine), poly(st-co-4vp) were prepared by soapless emulsion polymerization. Iron oxide was formed on the surface and inside of the poly(st-co-4vp) particles by thermal decompostion of iron pentacarbonyl. The obtained magnetic poly(st-co-4vp) particles was mondispersed and the average size was 250 nm. The magnetic poly(st-co-4vp) particles had 14% of iron oxide, which was identified as $Fe_3O_4$ by XRD. The magnetic poly(st-co-4vp) particles had superparamagnetism according to superconducting susceptometer (SQUID).

Synthesis of Hyper Crosslinked Polymer Particle Having Hydroxyl Group (하이드록시기를 갖는 Hyper Crosslinked 고분자 입자의 합성)

  • Jeon, Hyo-Jin;Kim, Dong-Ok;Park, Jea-Sung;Kim, Jong-Sik;Kim, Dong-Wook;Jung, Mi-Sun;Shin, Seong-Whan;Lee, Sang-Wook
    • Polymer(Korea)
    • /
    • v.35 no.1
    • /
    • pp.66-71
    • /
    • 2011
  • With the synthesis of hyper crosslinked polymer particle (HCPP), having microporous structure with hydroxyl functional group, synthesized via polymerization reaction consists of three stepssuspension polymerization, hyper crosslinking by Friedel-Craft catalysis and hydrolysis reaction, the effects of the ratio of each monomer, hyper crosslinking conditions and $CO_2$ supercritical drying on the variations of surface morphology, pore size & distribution and BET surface area of HCPP have been investigated. It was observed that the formation of surface crack or fracture of HCPP was intimately related with the degree of hyper crosslinking reaction between microphase separated domains. And the value of BET surface area of HCPP increased with the increase of reaction temperature, time and the amounts of solvent used in hyper crosslinking step. Moreover, $CO_2$ supercritical drying was proven to be a very effective method for removing stabilizer, unreacted monomers and oligomers from HCPP but needed to add methanol as a co-solvent for efficient removing of residual catalyst.

Study on the flow characteristics of the polymer reactors (고분자 반응기의 내부 유동 특성에 관한 연구)

  • Choi D. S.;Im Y. H.;Han S. P.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2002.05a
    • /
    • pp.134-139
    • /
    • 2002
  • This study is focused on investigating the characteristics of internal flow of the polymer reactor and its effect on the polymer quality. Four types of polymer reactor which have different kind of impeller, baffle and operation condition were calculated by CFD. Fluent 6 have been used to simulate mixing phenomena of reactor. According to the comparison of computational results and SEM photographs of polymer particle, distribution of turbulent dissipation rate greatly influences on the quality of polymer. So, distribution of turbulent dissipation rate to be important criterion to predict polymer quality.

  • PDF

Development of functional microsphere (I) - Formation and characteristics of poly(ethylene-co-vinyl acetate) microspheres via thermally induced phase separation - (기능성 마이크로스피어의 개발 (I) - 열유도 상분리에 의한 Poly(ethylene-co-vinyl acetate) 마이크로스피어의 제조와 특성 -)

  • 이신희;김효정;박수민
    • Textile Coloration and Finishing
    • /
    • v.15 no.4
    • /
    • pp.57-64
    • /
    • 2003
  • Poly(ethylene-co-vinyl acetate)(EVA) microspheres were prepared by a thermally induced phase separation. The microsphere formation occurred by the nucleation and growth mechanism in the metastable region. The diluent used was toluene. The microsphere formation and growth was followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by SEM observation and particle size analyzer, became broader when the polymer concentration was higher, the content of vinyl acetate in EVA copolymer was higher, and the cooling rate of EVA copolymer solution was lower.

Fabrication of PTFE/Al Composite Materials by Hot Press Process (가압소결에 의한 PTFE/AI 복합재료 제조)

  • 이길근;김우열
    • Journal of Powder Materials
    • /
    • v.9 no.2
    • /
    • pp.103-109
    • /
    • 2002
  • To investigate the fabrication possibility of a polymer particle dispersed metal matrix composite, polytetrafluorothylene (PTFE) particles were incorporated into the Al by the powder metallurgy process. The characteristics of a PTFE/Al composite were evaluated by measuring the density and hardness, and analysis of XRD, FT-Raman and microstructure. And wear properties of these composites were evaluated under the dry wear condition. It was possible to obtain the PTFE particles stably dispersed Al matrix composites by the hot press process at the sintering temperature of $500^{\circ}C$. The wear coefficient of a PTFE/Al compoite decreased with increasing of the volume fraction of PTFE. The wear weight of a PTFE/Al composite increased with increasing of the volume fractionof PTFE in the range of 0~10 vol.%PTFE, and showed maximum value at 10 vol.%PTFE, and then decreased at 20vol.%PTFE.

Synthesis of Hollow Silica Using PMMA Particle as a Template (PMMA 고분자 입자를 템플릿으로 이용한 실리카 중공체의 제조)

  • Hwang, Ha-Soo;Cho, Kye-Min;Park, In
    • Applied Chemistry for Engineering
    • /
    • v.21 no.3
    • /
    • pp.353-355
    • /
    • 2010
  • Poly(methyl methacrylate) (PMMA) particles were prepared by soap-free emulsion polymerization of MMA in the presence of a cationic initiator, 2,2'-azobis(2-methylpropionamidine) (AIBA). The Stober method has been adopted to coat silica on the surface of these cationic particles. Negatively charged silica precursors were coated onto cationic particle surfaces by electronic interaction. During the coating process, hollow particles were directly obtained by dissolution of PMMA.

Effect of Grain Size and Replacement Ratio on the Plastic Properties of Precipitated Calcium Carbonate Using Limestone as Raw Material

  • Baek, Chul Seoung;Cho, Kye Hong;Ahn, Ji-Whan
    • Journal of the Korean Ceramic Society
    • /
    • v.51 no.2
    • /
    • pp.127-131
    • /
    • 2014
  • Precipitated calcium carbonate(PCC) inorganic fillers for plastic offera higher replacement ratio with improved mechanical properties than any other inorganic fillers. Due to its secure economic feasibility, its fields of application areexpanding. For optimized PCC grain size and polymer replacement ratio, it is good to maintain at least $0.035{\mu}m$ grains and keep double the grain size of distance between particles, depending on the molecular weight and volume replacement rate of the polymer. PCC has unique characteristics, ie, with smaller grain size, dispersibility decreases, and if grain size is not homogenous, polymer cracking occurs. The maximum replacement ratio of PCC is approximately 30%, but in the range of 10 - 15% it produces the highest mechanical strength. When mixed with a biodegradable plastic like starch, it also improves initial environmental degradability.

Electrospraying of Polymeric Microparticles and its Application to Fabrication of Porous Membrane (고분자 미세입자의 전기분사와 다공성 박막 제작에의 응용)

  • Jeong, Young Hun;Oh, Hana
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.14 no.5
    • /
    • pp.126-133
    • /
    • 2015
  • Recently, there has been demand for polymeric porous membranes in various fields, such as environmental engineering, pharmaceutics, tissue engineering, drug delivery, biology, and fuel cells. In this study, it is proposed that a polymer particle-based porous membrane can be fabricated using electrospraying and sintering processes. Electrospraying can fabricate polymeric particles with diameters ranging from several micrometers to tens of nanometers without the cumbersome particle aggregation problem. Additionally, the particles can be sintered through thermo-compression under the glass transition temperature. In this study, a polymethyl methacrylate particle-based porous membrane with an average pore size of less than 500 nm is fabricated using the proposed method.