• Textile Coloration and Finishing
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• v.12 no.1
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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.

• Polymer(Korea)
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• v.26 no.2
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• pp.253-259
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• 2002

The objective of this study is to obtain thermally stable and low optical loss polymers for optical waveguiding materials. The crosslinkable poly (maleimide-co-methacrylate)s were synthesized using a pentafluorophenylmaleimide (an optical loss reducer), two methacrylate derivatives (refractive index controllers), and a glycidylmethacrylate (a crosslinker). These copolymers exhibited good thermal stability and could be thermally crosslinked by heat treatment. The refractive indexes of the copolymers could be precisely controlled by the variation of comonomer feed ratio, which was in the range of 1.45 ~ 1.49. These copolymers had very low birefringence of $6{ imes}10^{-4}$ ~ $1{ imes}10^{-4}$. These copolymers were crosslinked by contact printing and then developed by wet etching to obtain high quality waveguide pattern.

• Macromolecular Research
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• v.13 no.5
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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.

• Journal of Hydrogen and New Energy
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• v.27 no.6
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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.

• Polymer(Korea)
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• v.27 no.1
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• pp.17-25
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• 2003

Using atom transfer radical polymerization (ATRP), polystyrene macroinitiators and polystyrene-b-poly(t-butyl acrylate) (PS-b-P(tBA) block copolymers were synthesized by CuBr/PMDETA catalyst system in solution. After hydrolysis, polystyrene-b-poly(acrylic acid), amphiphilic block copolymers, were formed. Subsequent neutralization of polyacid block led to the block ionomers. The molecular weight of the synthesized PS-b-P(tBA) block copolymers was easily-controlled to 5000-10000 and their distributions were less than 1.2. The chemical structures of the synthesized block copolymers were characterized by $^1$H-NMR and FT-IR. In the DSC thermograms, $T_g$ appeared in the vicinity of 100 $^{\circ}C$ because of higher styrene content. In addition, the phase separation of the block ionomers was observed by TEM.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.7
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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).

• Polymer(Korea)
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• v.26 no.5
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• pp.582-588
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• 2002

The block copolymers were prepared by the ring opening polymerizati on of DL-lactide by poly(ethylene oxide) (PEO) with diethylzinc (ZnE$_2$) as a catalyst. When the feed ratio of PEO was over 30% relative to DL-lactide, the polymerization of DL-lactide took place from the PEO hydroxyl terminals to provide the desired A -B-A or A-B block copolymer. The block copolymers were made of films by cast method and the films obtained was drawn to 2.5 times at 60 $\^{C}$. At the same draw ratio, the tensile modulus of the films was decreased with increasing PEO content in the block copolymers. It was therefore suggested that the block copolymers comprising of PDLLA and PEO, had high potentials as the biomaterials with improved flexibility.

• Bulletin of the Korean Chemical Society
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• v.8 no.2
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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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• v.11 no.1
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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.

• Journal of Radiation Industry
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• v.6 no.2
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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.