• 제목/요약/키워드: Bio-polymer

검색결과 398건 처리시간 0.023초

폴리락틱산, 폴리카프로락톤, 폴리에틸렌 옥사이드 삼성분계 블렌드의 형태학적 변화와 이들이 의료용 스캐폴더의 기계적 특성에 미치는 영향 (Morphology Evolution of Poly(L-lactic acid) (PLLA), Poly(ε-caprolactone) (PCL) and Polyethylene Oxide (PEO) Ternary Blend and Their Effects on Mechanical Properties for Bio Scaffold Applications)

  • Ezzati, Peyman;Ghasemi, Ismaeil;Karrabi, Mohammad;Azizi, Hamed;Fortelny, Ivan
    • 폴리머
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    • 제38권4호
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    • pp.449-456
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    • 2014
  • Ternary blends of poly(L-lactic acid) (PLLA), poly(${\varepsilon}$-caprolactone) (PCL) and polyethylene oxide (PEO) were produced with different concentrations of components via melt blending. By leaching the PEO from the samples by water, porous materials were obtained with potential application for bio scaffolds. Sample porosity was evaluated by calculating the ratio of porous scaffold density (${\rho}^*$) to the non-porous material density (${\rho}_s$). Highest porosity (51.42%) was related to the samples containing 50 wt%. of PEO. Scanning electron microscopy (SEM) studies showed the best porosity resulted by decreasing PLLA/PCL ratio at constant concentration of PEO. Crystallization behavior of the ternary blend samples was studied using differential scanning calorimetry (DSC). Results revealed that the crystallinity of PLLA was improved by addition of PEO and PCL to the samples. The porosity plays a key role in governing the compression properties. Mechanical properties are presented by Gibson-Ashby model.

Electrospun Poly(Ether Sulfone) Membranes Impregnated with Nafion for High-Temperature Polymer Electrolyte Membrane Fuel Cells

  • Lee, Hong Yeon;Hwang, Hyung Kwon;Lee, Jin Goo;Jeon, Yukwon;Park, Dae-Hwan;Kim, Jong Hak;Shul, Yong-Gun
    • 전기화학회지
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    • 제19권1호
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    • pp.9-13
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    • 2016
  • Electrospun poly(ether sulfone) (PES) membrane impregnated with Nafion (PES-N) have been developed for high-temperature polymer-electrolyte membrane fuel cell (HT-PEMFC). The PES-N obtains highly thermal stability up to $430^{\circ}C$, which is higher than that of the commercial Nafion 212. The PES-N membrane shows a good proton conductivity of about $10^{-2}S\;cm^{-1}$ in a temperature range from $75^{\circ}C$ to $120^{\circ}C$. The membrane-electrode assembly (MEA) with the PES-N membrane exhibits a current density of $1.697A\;cm^{-2}$ at $75^{\circ}C$, and $0.813A\;cm^{-2}$ at $110^{\circ}C$ when the applied voltage is 0.6 V, whereas the MEA with the Nafion 212 membrane shows the current density of $0.647Acm^{-2}$ at $110^{\circ}C$. The results suggest that the PES-N can be a good candidate for a polymer electrolyte membrane of the HT-PEMFC.

유변학적 특성과 표면장력측정을 통한 음이온성 폴리머와 비이온성 계면활성제의 상호작용에 대한 연구 (Investigation of the Interactions between Anionic Polymer and Nonionic Surfactant with Rheological and Surface Tension Measurements)

  • 이정노;김동주;고하영
    • 한국응용과학기술학회지
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    • 제24권2호
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    • pp.160-166
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    • 2007
  • The rheological properties and surface tensions of polymer solutions and polymer-surfactant mixed solutions were investigated. The polymers used in this study were a homopolymer of acrylic acid crosslinked with an allyl ether of pentaerythritol, an allyl ether of sucrose, or an allyl ether of propylene (CARBOMER), acylate/C10-30 alkyl acylate crosspolymer (AAAC), and ammonium acryloydimethyltaurate/VP copolymer (ADTV). A solubilizing agent PEG-40 hydrogenated castor oil (HCO-40) and an emulsifying agent polyoxyethylene (20) sorbitan monostearate (POLYSORBATE 60) made the micelles intervening between AAAC polymers, resulting in the increase of viscosity. However, HCO-40 made this behavior over the wider range of surfactant concentration than POLYSORBATE 60. From the view point of surface tensions in the same range of surfactant concentration, AAAC/HCO-40 solution showed the area of increasing surface tension with surfactant concentration in contrast to the AAAC/POLYSORBATE 60 solution showing no increasing area.

Rheological characterization of nanoparticle filled polymeric systems

  • Kim, Byoung-Chul;Chae, Dong-Wook
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.219-219
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    • 2006
  • This study focuses on the effects of dispersion method of a nanoparticle in a polymer matrix such as melt mixing, solution blending, and in-situ polymerization on the physical properties of the nanocomposites. Introduction of a nanoparticle to a polymer resulted in some unusual physical properties. In some cases the nanoparticle played a role of a nucleating agent, leading to decreasing induction time to crystallization. In addition, the dispersion state of the nanoparticle in the polymer matrix also had a significant influence on the physical properties of the nanocomposites. Hence the method of introducing the nanoparticle to the polymer made contribution to the rheological properties of the nanocomposite systems.

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식물성 오일 기반 바이오 탄성체의 합성과 특성 (Synthesis and Characterization of Bio-Elastomer Based on Vegetable Oils)

  • 이혁;곽경환;김진국
    • Elastomers and Composites
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    • 제47권1호
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    • pp.30-35
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    • 2012
  • 새로운 스타폴리머인 바이오폴리부타디엔은 리빙 음이온중합이라는 고분자의 정밀 합성법을 통하여 분자량, 분자량분포, 조성 및 세부구조를 제어하였다. 리빙 음이온중합에 의해 n-BuLi으로 개시된 polybutadienyllithium(PBDLi)의 연쇄말단이 ESO(Epoxidized Soybean Oil)의 기능성 그룹과 커플링 반응을 일으키며 스타폴리머를 합성한다. 분자량이 1,000/5,000/10,000(g/mol)인 PBDLi을 중합하여 THF존재하에서 반응 후 GPC에 의한 분자량 및 arms분석과 $^1H$-NMR, FT-IR에 의한 고분자 구조 분석을 통하여 바이오폴리부타디엔의 합성을 확인하였다.