• 제목/요약/키워드: Radical polymerization

검색결과 319건 처리시간 0.027초

석조문화재를 위한 아크릴계 보존처리제의 무기친화성 개선 (Improvement in Inorganic Affinity of Acrylic Materials for Conservation Treatment of Stone Cultural Assets)

  • 김연철;김은영;김헝중
    • 폴리머
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    • 제34권1호
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    • pp.14-19
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    • 2010
  • 여러 원인에 의한 석조문화재의 풍화 손상을 저지할 목적으로 아크릴계 고분자를 이용하는 가압함침 보존 처리방법에서 함침된 고분자와 무기물질인 석재와의 친화성을 높이도록 silane계 아크릴 단량체의 사용을 연구하였다. 기본 단량체인 methyl metacrylate(MMA)에 vinyl trimethoxy silane(VTMS)의 함량을 변화시키고 라디칼 중합으로 MMA-VTMS 공중합체를 얻어 이들 공중합체의 유리전이온도, 평균분자량, 그리고 저장탄성률의 변화를 평가하여 benzoyl peroxide (BPO) 1 wt%, 중합시간 8시간, 그리고 VTMS 5 mol% 혼합의 경우(PMV5)가 최적 혼합비율과 중합조건임을 알 수 있었다. 실제 국내산 화강암과 풍화된 암석의 시편을 함침 보존처리한 후 수분 흡수율, 충격특성, 내산성 및 접착특성 등을 측정한 결과 MMA 단독 사용과 비교하여 PMV5의 경우 모든 특성에 있어서 개선되는 것을 확인하였다.

리튬이차전지 양극재인 유기라디칼 고분자의 산화법에 대한 연구 (Investigation of Oxidation Methods of Organic Radical Polymer for Cathode Material in Lithium Ion Batteries)

  • 이일복;김영훈;문지연;이철위;김다은;하경수;이동현;손형빈;윤성훈
    • 폴리머
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    • 제38권6호
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    • pp.827-831
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    • 2014
  • 라디칼 고분자화 반응 후 산화법을 이용하여 나이트록실 라디칼 고분자를 제조하였다. 두 가지 방법으로 산화된 라디칼 고분자의 라디칼 농도를 electroparamagnetic resonance spectroscopy(EPR) 법과 UV-visible absorption (UV-vis) 방법을 통하여 측정하고 이를 통해 과산화수소수-$Na_2WO_4$ 법으로 산화하였을 때 라디칼 농도가 97.6% 정도 높게 얻어짐을 확인하였다. 또한 UV-vis 법은 정량적인 분석이 어려우나 대략적인 라디칼 형성 정도를 평가하는데 유용함을 확인하였다. 제조된 유기라디칼 고분를 리튬이온전지 양극재로 적용한 결과 우수한 용량, 초기효율, 높은 속도 특성을 가짐을 알수 있었다.

SFRP Synthesis of Acenaphthylene Oligomers and Block Copolymers. Potential Light Harvesting Structures

  • Ali, Dildar;Ahmed, Zaheer;Dust, Julian M.;Kazmaier, Peter M.;Buncel, Erwin
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2377-2384
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    • 2011
  • Azo-acenaphthylene oligomers with repeating acenaphthylene units "n" up to 4, 5, 7, 17 and 19 have been prepared successfully using nitroxide mediated Stable Free Radical Polymerization (SFRP). Azo-acenaphthylene oligomers, reversibly end-capped by the stable nitroxide 2,2,6,6-tetramethyl-1-piperidinoxyl (TEMPO), were further reacted via radical addition to 4-(naphthalenemethoxy)styrene monomer for diblock co-polymer formation. Characterization of the oligomers and diblock co-polymers was accomplished using MALDI-MS supported by GPC (Gel Permeation Chromatography) and $^1H$ NMR spectrometry. MALDI-MS afforded definitive results by providing an inter-peak interval of 152 (m/z), corresponding to acenaphthylene monomer, and inter-peak interval of 260 (m/z) for the naphthalenemethoxystyrene monomer unit in block copolymers. Our study opens the way to control the number of repeat units in the oligomers. Further these oligomers can be tailored with various monomers for the formation of block copolymers.

HEMA가 치환된 Polyphosphazene의 공중합 및 콘택트렌즈 응용 (Copolymerization and Contact Lens Application of HEMA-Substituted Polyphosphazene)

  • 김태훈;성아영
    • 대한화학회지
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    • 제53권3호
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    • pp.340-344
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    • 2009
  • Phosphonitrillic chroride cyclic trimer 화합물을 $200{\sim}300\;{^{\circ}C}$ 하에 개환중합하여 선상 고분자를 얻 은 후 Grignard 시약 ($CH_2$=CH-MgBr)을 천천히 가하여 vinyl 기를 포함하는 polyphosphazene을 합성하였 으며, 이 폴리머를 HEMA(2-hydroxyethyl methacrylate)와 반응시켜 HEMA/vinyl-substituted polyphosphazene 을 얻었다. 이 고분자를 AIBN (azobisisobutyronitrile) 개시제 존재 하에서 교차결합제로 EGDMA(ethylene glycol dimethacrylate) 그리고 NVP (N-vinyl-pyrrolidone)을 혼합하여 공중합 시켰다. 얻어진 공중합체에 대한 측정 결과 산소투과율 (Dk/t)은 88로 측정되었으며, 함수율은 30.89% 그리고 가시광선 투과율은 87%로 나타났다. 이 자료로부터 이 공중합체가 우수한 콘택트렌즈 재료임을 발견하였다.

친환경 UV/EB 경화형 기능성 코팅 기술 (Environment-friendly Coating Technology of UV/EB Radiation Curing)

  • 이정복;이진휘;성기천
    • 한국응용과학기술학회지
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    • 제29권1호
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    • pp.159-173
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    • 2012
  • UV 경화기술은 라디칼 경화와 양이온 경화로서 크게 2 종류로 분류할 수 있다. 이 기술은 플라스틱과 금속간의 여러 기재에 대한 기능성을 개선하기 위해서 표면처리기술에 주로 초점이 맞추어져 왔다. 반면에, Electron beam 기술은 새로운 기능성 재료들을 창출하기 위해 중합공정뿐만 아니라 가교반응들을 다루었다. 이들 두 기술들은 종래의 열경화성 코팅과 비교할 때, 에너지이용 효율과 환경 친화적이어서, 건조와 경화 공정으로 부터 배출되는 탄산가스와 휘발성 유기물을 대폭 감소시킨다. 이 논문에서는 UV 경화 코팅에서 흔히 사용되는 라디칼 경화기술과, 최근의 있는 양이온 경화와 관련된 기술을 다룬 리뷰 논문이다.

Photochromism of A Styrene-Derived Polymer Having Pendant Phenoxyanthraquinones

  • Ju, Sang-Yong;Ahn, Kwang-Duk;Han, Dong-Keun;Suh, Dong-Hack;Kim, Jong-Man
    • Journal of Photoscience
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    • 제7권4호
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    • pp.131-133
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    • 2000
  • A Styrene-derived polymer having pendent phenoxyanthraquinones for photochromism was prepared by AIBN-initiated radical polymerization. Syntgesus of the monomers was straightforward and the polymer was obtained in 65% yield. Photoinduced rearrangement from the “trans” quinone forms to the “ana” quinone forms readily occurred both in solution and in film when the polymer was irradiated with UV light.

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Preparation of UV Curable Gel Polymer Electrolytes and Their Electrochemical Properties

  • Oh, Boo-Keun;Jung, Won-Il;Kim, Dong-Won;Rhee, Hee-Woo
    • Bulletin of the Korean Chemical Society
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    • 제23권5호
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    • pp.683-687
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    • 2002
  • We have investigated the effect of the number of ethylene oxide (EO) units inside poly(ethylene glycol)dimethacrylate (PEGDMA) on the ionic conductivity of its gelled polymer electrolyte, whose content ranges from 50 to 80 wt%. PEGDMA gelled polym er electrolytes, a crosslinked structure, were prepared using simple photo-induced radical polymerization by ultraviolet light. The effect of the number of EO on the ionic conductivity was clearly shown in samples of lower liquid electrolyte content. We have concluded that the ionic conductivity increased in proportion to both the number of EO units and the plasticizer content. We have also studied the electrochemical properties of 13PEGDMA (number of EO units is 13) gelled polymer electrolyte.

Allylamine계 항균제의 합성 및 그 항균성에 관한 연구(II) (A Study on the Antimicrobial Activity of Allylamine Polymers(II))

  • 심재윤;조예경;윤남식;박태수
    • 한국염색가공학회지
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    • 제11권6호
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    • pp.36-42
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    • 1999
  • The antimicrobial activities of the copolymer of N,N'-dimethyl- N,N'-diallyl ammonium chloride(DMDAAC) and diallyl amino(DA) were investigated. The copolymer of DMDAAC and DA was prepared by free radical Polymerization through an intra-intermolecular propagation mechanism ie, cyclopolymerization. The copolymer was, then, reacted with cyanuric chloride for reactivity with hydroxyl group of cellulose. Cotton fabrics were finished by synthesized polymer, and their antimicrobial activities and fastness to launderings were tested. Dichlorotriazinyl DMDAAC-DA copolymer has MIC value of 1ppm against S. aureus and 10ppm against K pneumoniae. The antimicrobial fastness of the finished cotton to launderings were good enough to show colony reduction above 70% against S. aureus and K pneumoniae after 50 repeated laundering in anionic commercial detergent. Optimum treatment concentrations of the polymer were 0.5% in cold pad-batch method, and 0.1% in pad-dry method.

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Synthesis of New Phospholipid Biocompatible Textile Finishing Agent

  • Ko, Yong-Il;Yi, Jong-Woo;Kim, Sung-Hoon;Bae, Jin-Seok
    • 한국염색가공학회지
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    • 제22권4호
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    • pp.293-299
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    • 2010
  • A methacrylate monomer having phospholipid polar group and cell membrane structure is known as highly biocompatible. Based on these properties, new biocompatible multi-functional textile finishing agent was developed using phospolipid copolymer. 2-Methacryloyloxyethyl phosphorylcholine (MPCE) was synthesized using 2-hydroxyethyl methacrylate (HEMA), 2-chloro-2-oxo-1,3,2-dioxaphospholane (COP) and triethylamine (TEA), and then polymerized to prepare MPCE copolymer by radical polymerization using azobisisobutyronitrile(AIBN). The structures of MPCE was characterized by FT-IR and 1H NMR and will be evaluated as textile finishing agent in further study.

폴리아크릴산-폴리에칠렌글리콜 IPN공중합체 마트릭스의 팽윤 및 약물방출 (Controlled Drug Release from Polyacrylic Acid-Polyethylene Glycol Interpenetrating Networks)

  • 김윤정;김길수;이승진
    • Journal of Pharmaceutical Investigation
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    • 제24권4호
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    • pp.257-263
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    • 1994
  • The interpenetrating polymer networks (IPNs) of polyacrylic acid (PAA)-polyethylene glycol (PEG) were synthesized via crosslinking of PEG and simultaneous free radical polymerization of PAA. The equilibrium swelling of the IPNs matrices, ranged from 40% to 95%, was varied to a great extent as compared with PAA homopolymer due to the interpolymer interaction between PAA and PEG. The drug release kinetics of drug loaded matrices was significantly affected by the charge of drugs as well as interpolymer complexation.

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