• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 춘계 총회 및 학술발표회
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• pp.99-101
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• 1998

1. Introduction : The conventional grafting polymerization technique requires chemically reactive groups on the surface as well as on the polymer chains. For this reason, a series of prefunctionalization steps are necessary for covalent grafting. The surface prefunctionalizational technique for grafting can be used to ionization radiation, UV, plasma, ion beam or chemical initiators. Of these techniques, radiation method is one of the useful methods because of uniform and rapid creation of active radical sites without catalytic contamination in grafted samples. If the diffusion of monomer into polymer is large enough to come to the inside of polymer substrate, a homogeneous and uniform grafting reaction can be carried out throughout the whole polymer substrate. Radiation-induced grafting method may attach specific functional moieties to a polymeric substrate, such as preirradiation and simultaneous irradiation. The former is irradiated at backbone polymer in vacuum or nitrogen gas and air, and then subsequent monomer grafting by trapped or peroxy radicals, while the latter is irradiated at backbone polymer in the presence of the monomer. Therefore, radiation-induced polymerization can be used to modification of the chemical and physical properties of the polymeric materials and has attracted considerable interest because it imparts desirable properties such as blood compatibility. membrane quality, ion excahnge, dyeability, protein adsorption, and immobilization of bioactive materials. Synthesizing biocompatible materials by radiation method such as preirradiation or simultaneous irradiation has often used $\gamma$-rays to graft hydrophilic monomers onto hydrophobic polymer substrates. In this work, in attempt to produce surfaces that show low levels of anti-fouling of bovine serum albumin(BSA) solutions, hydroxyethyl methacrylate(HEMA) was grafted polypropylene membrane surfaces by preirradiation technique. The anti-fouling effect of the polypropylene membrane after grafting was examined by permeation BSA solution.

• BMB Reports
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• 제49권12호
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• pp.655-661
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• 2016

Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate's properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

• Elastomers and Composites
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• 제24권2호
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• pp.110-121
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• 1989

The radical initiated graft copolymerization of acrylonitrile(AN) and 4-chlorostyrene(4-Clst) onto ethylene-propylene-diene terpolymer(EPDM) rubber was investigated under various conditions. Graft copolymer(AU-EPDM-4-Clst) was isolated b: selective solvent extraction and identified by using IR spectroscopy. The percent grafting is determined as a function of solvent, reaction time, and monomer mole ratio. Percent grafting decreased in the order of tetrahydrofuran(THF)>THF/ethyl acetate(EA)(1 : 1)>cyclohexane/EA(1 : 1)>n-hexane/EA(1 : 1). Grafting increased continuously with increasing the reaction time up to 40 hr, beyond which the grafting levelled off. It was observed that percent grafting increased as increasing [4-Clst]/[AN] mole ratio, but decreased when [4-Clst]/[AN] mole ratio was higher than 1.60. The light resistance of graft copolymer(AN-EPDM-4-Clst) was better than that of ABS.

• 한국환경과학회지
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• 제23권1호
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• pp.105-112
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• 2014

With the incorporation of hydrogen peroxide($H_2O_2$) and NaLS as an initiator and emulsifier, acrylic acid monomer was graft copolymerized with sodium alginate prepared from alginic acid, and then the grafted copolymer was confirmed through IR spectrometer. When the amounts of acrylic acid increased the grafting also showed increasing trend. While the contents of hydrogen peroxide was varied in the aqueous sodium alginate solution, the grafting efficiency decreased gradually as the amounts of initiator increased.

• Elastomers and Composites
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• 제50권2호
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• pp.119-125
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• 2015

Because of their low surface free energy and absence of polar groups at the surface, polyolefins are substrates whose wetting and adhesion are very difficult. Free radical grafting of monomers to backbone polymer is one of the most attractive ways for the chemical modification of polymers. Synthesis of graft copolymer through graft polymerizations of PE and/or PP with phthalic anhydride (PhAn) was made and FTIR spectra of the graft polymer were the examined. And also the effects of phthalic anhydride content on the grafting ratio, thermal properties and contact angle of the graft polymer were examined.

• Elastomers and Composites
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• 제26권2호
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• pp.109-114
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• 1991

The graft copolymerization of chloroprene rubber with methyl methacrylate in toluene solution has been carried out varying the concentration of monomer, initiator, CR, reaction time, and reaction temperature, etc.. It is observed that the grafting reaction follows conventional kinetic behavior under the present experimental conditions. Identification of grafting on to chloroprene rubber was obtained through characterization of the graft copolymer by infrared spectrometer.

• 폴리머
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• 제39권1호
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• pp.180-184
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• 2015

폴리프로필렌(PP)으로 그래프트된 그래핀 옥사이드(PP-grafted GO)는 2-bromoisobutyryl 그룹을 가진 GO(GO-Br)와 하이드록시 그룹을 가진 PP(PP-OH)와의 "grafting-to" 화학반응을 통하여 제조하였다. GO-Br은 GO와 2-bromoisobutyryl bromide를 염기촉매 하에서 반응시켜 얻을 수 있었고, PP-OH는 maleic anhydride가 그래프트된 PP(PP-MAH)와 ethanolamine과 반응하여 제조하였다. 제조된 PP-grafted GO는 PP-OH에 비하여 녹는점이 높은 온도로 이동하였고, 열적 안정성은 GO와 PP-OH에 비하여 우수한 것을 확인하였다. 이러한 결과는 그래프트된 PP 고분자가 GO의 열적 안정성을 향상시키는 것으로 판단된다. 또한 PP-grafted GO의 표면은 GO-Br에 비하여 거칠기가 증가되는 것을 확인하여 PP가 GO 표면에 화학적으로 결합한 것을 알 수 있었다. 제조된 PP-grafted GO의 분석은 FTIR, Raman, DSC, TGA, SEM과 같은 다양한 분석장비를 이용하여 수행하였다.

• 폴리머
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• 제33권3호
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• pp.268-271
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• 2009

본 연구에서는 방사선 동시조사법에 의해 제조된 FEP-g-PSSA 막 단면을 SEM-EDX 기기로 분석하여 스티렌 술폰산 고분자(PSSA)의 막 내부로의 분포 경향을 연구하였다. 본 실험에서는 그래프트율, FEP 필름 두께, 선량률, 그래프팅 용매 등 여러 조사조건이 그래프트 고분자의 분포에 미치는 영향을 중점적으로 연구하였다. 실험 결과 균일하게 그래프트된 FEP-g-PSSA 막을 얻기 위해서는 필름 두께가 증가할수록 높은 그래프트율이 요구되어지고, 같은 조사 선량에서는 낮은 조사 선량률로 그래프트하는 것이 효과적임을 보여준다.

• 폴리머
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• 제38권3호
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• pp.293-298
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• 2014

본 연구에서는 방사선을 이용하여 다공성 polytetrafluoroethylene(PTFE) 지지체에 acrylonitrile(AN)과 친수성 작용기를 가진 sodium allylsulfonate(SAS)를 접목시켜 복합 연료전지막의 지지체로 사용되는 친수화 다공성 지지체를 제조하였다. SAS/AN의 몰비율, 단량체 농도, 방사선의 조사선량에 변화를 주어 제조된 지지체의 물성을 평가하였다. 제조된 지지체의 FTIR 분석을 통하여 각 단량체들이 다공성 PTFE 지지체에 성공적으로 그래프팅되었음을 확인하였다. 또한 FE-SEM과 gurley number 측정을 이용하여 그래프트율이 증가할수록 지지체 표면의 기공이 감소하는 것을 관찰하였고, 그래프트율, 접촉각, TBO(toluidine blue O) uptake 분석을 통해 그래프트율이 증가됨에 따라 제조된 지지체의 친수화도가 증가하는 것을 확인하였다.

• 한국고분자학회지:고분자과학과기술
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• 제9권3호
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• pp.193-199
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• 1998