• 제목/요약/키워드: Graft polymerization

검색결과 177건 처리시간 0.024초

키토산과 폴리에틸렌글리콜 모노메타크릴레이트의 그라프트중합과 약물(Vitamin B12)방출에 관한 연구 (Studies on the Graft Polymerization of Polyethyleneglycol Monomethacrylate onto Chitosan and Drug(Vitamin B12) Permeation Behavior)

  • 정주은;정병옥;장병권;최규석
    • 공업화학
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    • 제5권3호
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    • pp.524-536
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    • 1994
  • 생체적합성이 좋은 천연고분자인 chitosan에 수용성의 비닐계 단량체인 polyethyleneglycol monomethacrylate series를 그라프트중합시켜 그 반응조건과 물성을 검토하였다. 그라프트중합은 ethylene oxide 부가몰수에 따라 PE-90, PE-200, PE-350의 세 가지 단량체에 ceric ammonium nitrate(CAN)를 개시제로 사용하였으며, 중합에서 개시제의 농도, 단량체의 농도, 반응온도, 반응시간이 총전환율, 그라프트율, 그라프트효율에 미치는 영향을 조사하여 최적조건을 규명하였다. 반응은 개시제농도 $4{\sim}5{\times}10^{-3}M$, 단량체농도 0.5~0.6M, 반응시간 2~3시간, 반응온도 $40^{\circ}C$에서 최고의 그라프트율과 총전환율을 나타냈다. 합성한 공중합체의 열적 성질, 용해성 및 점성도를 검토한 결과 고농도의 개시제를 사용하면 그라프트 중합체는 chitosan의 특성을 급격히 감소시켰다. 고유점성도의 경우, chitosan-g-PE-90이 2.81dl/g, chitosan-g-PE-200이 3.01dl/g, chitosan-g-PE-350이 4.93d1/g으로 증가하는 경향이 나타났다. 공중합체를 막으로 성형하여 그라프트율과 polyethyleneglycol monomethacrylates의 ethylene oxide 부가몰수에 따른 공중합체의 기계적 물성과 함수율을 측정하였다. 가교화 공중합체막은 150분 이내에 함수율이 평형에 이르렀다. 공중합체의 물성은 그라프트율과 ethylene oxide 부가몰수의 영향을 받았으며 chitosan의 기계적 물성과 함수율이 공중합체에서 증가되었음을 확인하였으며 그라프트율이 증가함에 따라 vitamin $B_{12}$의 투과량도 증가하였다.

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Stimuli-Responsive Micelles of Amphiphilic and Bis-hydrophilic Block and Graft Copolymers

  • Muller Axel H. E.
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.101-101
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    • 2006
  • We have studied the micellisation of poly(n-butyl acrylate)-block-poly(acrylic acid) and poly(n-butyl acrylate)-graft-poly(acrylic acid) in aqueous solution. The size and structure of the formed micelles was elucidated by scattering and imaging techniques. The micelle structure depends on pH, composition, and topology: graft copolymers form much smaller micelles that block copolymers of similar composition. We have also synthesized block copolymers of acrylic acid and N-isopropylacrylamide (NIPAAm) or N,N-diethylacrylamide (DEAAm). Due to the LCST of polyNIPAAm and polyDEAAm, these block copolymers spontaneously form micelles upon heating and they form inverse micelles upon decreasing pH below 4. If the LCST block is much longer than the PAA one, this presents a very convenient way to prepare crew-cut micelles. The polymers have been successfully used as stabilizers in emulsion polymerization. They also have been conjugated to streptavidin. The conjugates reversibly form mesoscopic particles on heating.

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스티렌-부타디엔-스티렌 블록 공중합체(共重合體)의 개질(改質)과 그 특성(特性) (Modification of Styrene-Butadiene-Styrene Block Copolymer and the Properties of Graft Products)

  • 왕은진;윤정식;유종선;백남철
    • Elastomers and Composites
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    • 제25권4호
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    • pp.273-279
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    • 1990
  • The graft polymerization of 2-hydroxyethylmethacrylate(HEMA) and vinyltriethoxysilane(VTES) onto styrene-butadiene-styrene block copolymer(SBS) was carried out in toluene, with radical initiator such as benzoyl peroxide(BPO) and 2, 2'-azo-bis-isobutyronitrile(AIBIN) under nitrogen atmosphere. The degree of grafting was increased with the increases of the reaction temperature and time. And the effeciency of BPO was superior to that of AIBN. The mechanical properties and molecular weight of graft products were measured and the applicability as adhesive of plasticized PVC leather was examined.

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Radiolytic Immobilization of Lipase on Poly(glycidyl methacrylate )-grafted Polyethylene Microbeads

  • Choi Seong-Ho;Lee Kwang-Pill;Kang Hee-Dong;Park Hyun Gyu
    • Macromolecular Research
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    • 제12권6호
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    • pp.586-592
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    • 2004
  • Poly(glycidyl methacrylate)-grafted polyethylene microbeads (POPM) presenting epoxy groups were prepared by radiation-induced graft polymerization of glycidyl methacrylate on the polyethylene microbead. The obtained POPM was characterized by IR spectroscopic, X-ray photoelectrons spectroscopy (XPS), scanning electron microscope (SEM), and thermal analyses. Furthermore, the abundance of epoxy groups on the POPM was determined by titration and elemental analysis after amination. The epoxy group content was calculated to be in the range 0.29-0.34 mmol/g when using the titration method, but in the range 0.53-0.59 mmol./g when using elemental analysis (EA) after amination. The lipase was immobilized to the epoxy groups of the POPM under various experi­mental conditions, including changes to the pH and the epoxy group content. The activity of the lipase-immobilized POPM was in the range from 160 to 500 unit/mg-min. The activity of the lipase-immobilized POPM increased upon increasing the epoxy group content. The lipase-immobilized POPM was characterized additionally by SEM, elec­tron spectroscopy for chemical analysis (ESCA), and EA.

수소이온 전도성 가지형 공중합체 전해질막 제조 및 분석 (Synthesis and Characterization of Proton Conducting Graft Copolymer Membranes)

  • 노동규;고종관;서진아;김종학
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.126.2-126.2
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    • 2010
  • The "grafting from" technology to prepare the well-defined microphase-separated structure of polymer using atom transfer radical polymerization (ATRP) will be introduced in this presentation. Various amphiphilic comb copolymers were synthesized through this approach using poly (vinylidene fluoride) (PVDF), poly (vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-co-CTFE) and poly(vinyl chloride) (PVC) as a macroinitiator. Hydrophilic side chains such as poly (styrene sulfonic acid) (PSSA) or poly (sulfopropyl methacrylate) (PSPMA) were grafted from the mains chains using direct initiation of the chlorine atoms. The structure of mass transport channels has been controlled and fixed by crosslinking the hydrophobic domains, which also provides the greater mechanical properties of membranes. Successful synthesis and microphase-separated structure of the polymer were confirmed by $^1H$ NMR, FT-IR spectroscopy and TEM. The grafted/crosslinked membranes exhibited good mechanical properties (400 MPa of Young's modulus) and high thermal stability (up to $300^{\circ}C$), as determined by a universal testing machine (UTM) and TGA, respectively.

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피혁 가공 부산물을 이용한 마이크로 콜라겐 분말의 효율적인 제조와 특성 연구 (A Study on an Efficient Manufacturing Process of Fine Collagen Powder Using Leather By-Product)

  • 박재형;백인규;김용범
    • 유기물자원화
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    • 제15권4호
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    • pp.100-106
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    • 2007
  • 피혁 제조 공정중 탈모 공정 이후 나피를 분할(Splitting)하여 얻어지는 피혁 가공 부산물(Limed pelt scrap)을 이용하여 탈회 및 탈지 과정의 전처리 공정을 거친 뒤 비크롬 탄닝과 열처리에 의한 방법과 glycidyl methacrylate (GMA)와 MMA와 같은 아크릴 모노머를 이용한 그라프트 공중합을 이용한 방법으로 우수한 내열성을 갖는 미세 콜라겐 분말을 제조하였다. 물성의 비교에서 본 연구의 방법으로 생산된 콜라겐 분말들이 열분해 온도, 열 저항성, 수분변화, 입도분포 등에서 더 나은 특성을 보였다.

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Preparation for Protein Separation of an Ion-Exchange Polymeric Stationary Phase Presenting Amino Acid and Amine Units Through Surface Graft Polymerization

  • Choi Seong-Ho;Lee Kwang-Pill;Shin Chang-Ho
    • Macromolecular Research
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    • 제13권1호
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    • pp.39-44
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    • 2005
  • Ion-exchange polymeric stationary phases presenting amino acid and amino groups were prepared by the surface grafting of glycidyl methacrylate onto a silica gel surface and subsequent amination. Three kinds of amino acids-L-arginine (Arg), D-lysine (Lys), and D-histine (His)-were used in this study. An ion-exchange polymeric stationary phase presenting ethylene diamine (EDA) was also prepared by surface graft polymerization. Separation of the model proteins bovine serum albumin (BSA), chick egg albumin (CEA), and hemoglobin (Hb) was performed using the amino acid- and amine-derived columns. In separating the CEA/BSA mixture, the resolution time of BSA was longer than that of CEA when using the EDA column, whereas the resolution time of BSA was shorter than that of CEA when using the Arg, Lys, and His columns. In the separation of the Hb/BSA mixture, the resolution time of BSA was longer than that of Hb in the EDA column, whereas the resolution time of BSA was shorter than that of Hb in the amino acid columns (D-Lys, L-Arg, and D-His).