• 한국염색가공학회지
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• 제12권1호
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• pp.61-67
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• 2000

This study was carried out to develope antimicrobial artificial suede by coating with water soluble polyurethane resin and the copolymer of N,N'-dialkyl-N,N'-dialkyl ammonium chloride (DADAAC) and acrylamide as a antimicrobial additve. The copolymer of DADAAC and acrylamide was synthesized by free radical initiation and intra-intermolecular propagation, and the prepared copolymers had sufficient compatibility with water soluble polyurethane resin. The MIC values of the prepared copolymers and antimicrobial characteristics of the artificial suede coated by polyurethane were evaluated. With the increase in the proportion of DADAAC, which is antimicrobially active part in the DADAAC/acrylamide copolymers, the MIC value becomes lower. The MIC value of DADAAC-AA (1 : 1) copolymer is below 30 ppm against S. aureus, and below 90 ppm against K pneumoniae. The artificial suede coated by water soluble polyurethane resin with 1.0% owl concentration of DADAAC/acrylamide copolymer has good antimicrobial fastness as to show colony reduction of above 90% and 80% against S. aureus and K. pneumoniae respectively in the shake flask test after 10 times of washing, and above 95% and 85% after 10 times of dry-cleaning. The elastic recovery of coated suede fabric is not affected up to 1.0% owf concentration of DADAAC-AA copolymer in the polyurethane coating.

• 폴리머
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• 제26권2호
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• pp.253-259
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• 2002

본 연구는 내열성, 저광학손실 광도파로용 고분자재료를 합성하고 그 물성을 조사한 것이다. 열안정성을 높이고 광학손실을 줄이기 위한 pentafluorophenylmaleimide와 복굴절률을 낮추기 위한 두가지 methacrylate 유도체와 가교제 역할을 하는 glycidylmethacrylate를 삼원 공중합하여 광가교가 가능한 poly(maleimide-co-methacrylate)를 합성하였다. 합성된 고분자들은 높은 열안정성을 나타내었고, 열처리에 의해서 가교가 됨을 확인하였다. 고분자의 굴절율은 공중합 비율에 의해서 조절가능하였고, 1.45~l.49 범위의 고분자가 합성되었다. 복굴절은$6{ imes}10^{-4}$ ~ $1{ imes}10^{-4}$ 범위의 낮은 값을 나타내었다. 이 고분자와 광개시제를 사용하여 접촉 인쇄 방식에 의한 노광과 습식 현상을 통해 깨끗한 광도파로 패턴을 얻을 수 있었다.

• Macromolecular Research
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• 제13권5호
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• pp.373-384
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• 2005

Novel pH-sensitive moieties containing an s-triazine ring were synthesized with sulfonamide and secondary amino groups. The synthesized pH-sensitive moieties were used for the synthesis of a pH-sensitive amphiphilic ABA triblock copolymer. The pH-sensitive triblock copolymer was composed of diblock copolymers, methoxy poly(ethylene glycol)-poly ($\varepsilon$-caprolactone-co-D,L-lactide) (MPEG-PCLA), and pH-sensitive moiety. These copolymers could be dissolved molecularly in both acidic and basic aqueous media at room temperature due to secondary amino and sulfonamide groups. The synthesized s-triazine rings containing pH-sensitive compounds were characterized by ${^1}H-NMR,\;{^13}C-NMR$, and LC/MSD spectral data. The synthesized diblock and triblock copolymers were also characterized by ${^1}H-NMR$ and GPC analyses. The critical micelle concentrations at various pH conditions were determined by fluorescence technique using pyrene as a probe. Furthermore, the micellization and demicellization study of the triblock copolymer was done with pH-sensitive groups. The sensitivity towards pH change was further established by acid-base titration.

• 한국수소및신에너지학회논문집
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• 제27권6호
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• pp.660-669
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• 2016

A fluorinated-sulfonated, hydrophobic-hydrophilic copolymer was planed subsequently synthesized using typical nucleophilic substitution polycondensation reaction. A novel AB and ABA (or BAB) block copolymers were synthesized using sBCPSBP (sulfonated 4,4'-bis[4-chlorophenyl)sulfonyl]-1,1'-biphenyl), DHN (1,5-dihydroxynaphthalene), DFBP (decafluorobiphenyl) and HFIP (4,4'-hexafluoroisopropylidenediphenol). All block copolymers were easily cast and made into clear films. The structure and synthesized copolymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (Fourier transform infrared). TGA (Thermogravimetric analysis) and DSC (differential scanning calorimetry) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. Hydrophobic/hydrophilic phase separation and clear ionic aggregate block morpology was confirmed in both triblock and diblock copolymer in AFM (atomic force microscopy), which may be highly related to their proton transport ability. A sulfonated BAB triblock copolymer membrane with an ion-exchange capacity (IEC) of 0.6 meq/g has a maximum ion conductivity of 40.3 mS/cm at $90^{\circ}C$ and 100% relative humidity.

• 폴리머
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• 제27권1호
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• pp.17-25
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• 2003

원자 이동 라디칼 중합 (ATRP)을 이용하여 CuBr/N,N,N',N",N"-pentamethyldiethylene triamine 촉매 시스템하에서 용액중합으로 polystyrene 거대 개시제와 polystyrene-b-t-poly(butyl acrylate) (PS-b-P(tBA)) 블록 공중합체를 합성한 후, 가수분해를 통해 polystrene-b-poly(acrylic acid) 양친매성 블록 공중합체를 얻었다. 또한, 이를 중화하여 블록 이오노머를 제조하였다. 합청된 PS-b-P(tBA) 블록 공중합체는 분자량이 5000-10000 정도로 조절되었고, 분자량 분포도 1.2 이하로 비교적 좁게 나타났다. 공중합체는 $^1$H-NMR, FT-IR로 분석하였으며, DSC로 열적 성질을 측정한 결과, styrene의 비율이 더 많기 때문에 100 $^{\circ}C$ 근처에서 T$_{g}$가 나타났으며, TEM을 통해 이온 그룹의 상분리를 확인하였다.분리를 확인하였다.

• 한국전기전자재료학회논문지
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• 제23권7호
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• pp.539-544
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• 2010

We have synthesized new blue electroluminescent polyalkylfluorene-based copolymers [poly(F-co-Py)x:y, where x:y = 99:1 or 95:5 mole ratios] containing the hole-injecting pyrazole derivative [3,3'-(4,6-bis(octyloxy)-1,3-phenylene)bis(1,5-diphenyl-4,5-dihydro-1H-pyrazole] through Ni(0) mediated polymerization, and their electroluminescent properties were investigated. Electroluminescent (EL) devices were fabricated with ITO / PEDOT:PSS (110 nm) / copolymers or PF homopolymer (80 nm) / Ca (50 nm) / Al (200 nm) configuration. Each EL device constructed from the copolymer exhibited significantly enhanced brightness and efficiency compared with a device constructed from the PF homopolymer. The EL device constructed with poly(F-co-Py)99:1 exhibited the highest luminous efficiency and brightness (0.95 cd/A and $2,907\;cd/m^2$, respectively). The achieved luminous efficiency was an excellent result, providing almost a 4-fold improvement on the efficiency obtainable with the a PF homopolymer device. This enhanced efficiency of the copolymer devices results from their improved hole injection and more efficient charge carrier balance, which arises from the HOMO level (~5.83 eV) of the poly(F-co-Py)99:1 copolymer, which is higher than that of the PF homopolyme (~5.90 eV).

• 폴리머
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• 제26권5호
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• pp.582-588
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• 2002

DL-lactide의 단점을 개선할 목적으로 개환중합법으로 촉매로서 diethylzinc (ZnEt$_2$)를 사용하여, poly(ethylene oxide) (PEO)를 세그먼트로서 도입한 블록공중합체를 합성하였다. 그 결과 DL-lactide에 대한 PEO세그먼트의 첨가비가 30% 이상에서는 조성비가 급격히 증가하였으며, 이들 공중합체를 캐스트법에 의해 필름으로 제작하여 6$0^{\circ}C$에서 2.5배 연신하여 인장실험을 실시하였다. 모든 공중합체 필름은 PDLLA에 대한 PEO에스테르 첨가비의 증대에 따라 탄성율이 저하되는 것이 관찰되어 세그먼트 도입에 의한 유연성의 증대를 확인하였으며 유연성이 요구되는 의용재료로서의 기대를 높였다.

• Bulletin of the Korean Chemical Society
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• 제8권2호
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• pp.102-105
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• 1987

2-Methoxy-6-methyl-3,4-dihydro-2H-pyran ($1_a$), 2-ethoxy-3,6-dimethyl-3,4-dihydro-2H-pyran ($1_b$), and 2-ethoxy-3-methyl-6-ethyl-3,4-dihydro-2H-pyran ($1_c$) were prepared by (4 + 2) cycloaddition reaction from the corresponding vinyl ketones and alkyl vinyl ethers. Compounds $1_{a-c}$ were ring-open polymerized by cationic catalyst to obtain alternating head-to-head (H-H) copolymers. For comparison, copolymer of head-to-tail (H-T) was also prepared by free radical copolymerization of the mixture of the corresponding monomers. The H-H copolymer exhibited some differences in its $^1H$ NMR and IR spectra. However, significant differences were showed between the H-H and H-T copolymers in the $^{13}C$ NMR spectra. Also noteworthy was that$T_g$ value of H-H copolymer was higher than that of the corresponding H-T structure. Decomposition temperature of the H-H copolymer was lower than that of the H-T copolymer. All the H-H and H-T copolymers were soluble in common solvents.

• Bulletin of the Korean Chemical Society
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• 제11권1호
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• pp.11-15
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• 1990

The temperature dependence of electrical conductivities and thermoelectric power of $I_2$-doped poly(1,4-penylene vinylene-co-2,5-dimethoxy-1,4-phenylene vinylene)s [poly(PV-co-DMPV)] and poly(1,4-phenylene vinylene-co-2,5-thienylene vinylene)s [poly(PV-co-TV)] were studied. The former copolymers were also doped with $FeCl_3$. All the samples used were in thin film forms. The temperature dependence of electrical conductivity implies that the variable range hopping conduction mechanism applises to these systems. The activation energy for the electrical conduction in dimethoxy-phenylene vinylene (DMPV) copolymers ranged from about 7 to 30 meV depending on the polymer composition and the nature of the dopant. It was significantly higher for $I_2$-doped thienylene vinylene (TV) copolymers, namely 90-200 meV. The values of the room temperature thermoelectric power were $30-70{\mu}V/K$ for DMPV copolymer and $100-800{\mu}V/K$ for TV copolymers. Anisotropy in the electrical conductivities was also studied for oriented films obtained by uniaxial stretching of the precursor polymer films.

• 방사선산업학회지
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• 제6권2호
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• pp.171-176
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• 2012

In this study, a crosslinked poly(styrene-butadiene-styrene) [SBS] block copolymers were prepared by using gamma ray irradiation method. The effects of various radiation doses on the degree of crosslinking, thermo property, and morphology of crosslinked SBS block copolymer were investigated. The degree of crosslinking of crosslinked SBS block copolymers were measured by gel-fraction and FT-IR. It was found that the degree of crosslinking of crosslinked SBS block copolymers increases with increase of the irradiation dose while the TGA result shows that the initial degradation temperature of irradiated SBS block copolymer was shifted to lower temperature with increasing irradiation dose. These results indicate that degradation reaction also occurs when SBS block copolymer is exposed to gamma ray irradiation for crosslinking reaction. The SAXS and FE-SEM results indicate that the phase separation of the styrene block and butadiene block was reduced with increasing irradiation dose.