• Journal of the Korean Chemical Society
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• v.60 no.4
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• pp.286-291
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• 2016

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.283-287
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• 1993

p-(2,2,3,3-Tetracyanocyclopropyl)phenyl acrylate (3a) and p-(2,2,3,3-tetracyanocyclopropyl)phenyl methacrylate (3b) were prepared by the reactions of bromomalononitrile with p-acryloyloxybenzylidenemalononitrile (2a) or p-methacryloyloxy-benzylidenemalononitrile (2b), respectively. Compounds 3a and 3b were polymerized with free radical initiators to obtain the polymers with multicyano functionalities in the cyclopropane ring. The resulting polymer 4a was soluble in acetone but the polymer 4b was not soluble in common solvents. The inherent viscosities of polymers 4a were in the range of 0.10-0.15 dL/g in acetone and those of 4b were in the range of 0.20-0.30 dL/g in 98% sulfuric acid. Solution-cast films were cloudy and brittle, showing $T_g$ values in the range of 106-125$^{\circ}$C.

• Macromolecular Research
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• v.14 no.5
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• pp.539-544
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• 2006

2-Furancarboxaldehyde-2-pyridinylhydrazone (FPH) and 5-methyl-2-furancarboxaldehyde-2-pyridinylhydrazone (MFPH) were synthesized and used as tridentate ligands of copper (I) bromide for the atom transfer radical polymerization of methyl methacrylate (MMA) and styrene. The polymerization of methyl methacrylate achieved high conversion and yielded polymers with a good control of molecular weight and low polydispersity (PDI=1.33). Higher PDI were observed in the polymerization of styrene. Using 1-phenyl ethylbromide (PEBr) and ethyl 2-bromoisobutyrate (EBiB) as model compounds for the polymeric chain ends, the activation rate constants of the new catalytic systems were measured. These results were correlated with the polymerization results and compared with another catalytic system previously reported.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.1-5
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• 2018

In this study, we designed and synthesized novel thermal radical initiators of BTAP (1-phenyl-3,3-dipropyltriazene), BTACP (1-(phenyldiazenyl)pyrrolidine), BTACH (1-(phenyldiazenyl)piperidine), and BTACH7 (1-(phenyldiazenyl)azepane) based on a triazene moiety to provide a thermal initiator for radical polymerization. The synthetic method is valuable due to the simplicity. In addition, the synthesized thermal initiator did not affect the color of the polymer. Among the four initiators, the polymerization time for the BTACH of the 6-membered ring decreased by 67%, as opposed to the polymerization time without initiator. Conversion after polymerization was over 92%. DSC experiments also showed that the initiator with hexagonal rings had the lowest peak polymerization temperature of $160^{\circ}C$. Our study suggests a promising new initiator system that is effective for radical polymerization.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.95-96
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• 2006

Surface modification of clay minerals has become increasingly important for improving the practical applications of clays such as polymeric nanocomposites. We used the copolymer as modifiers having phenyl components, and successfully developed a route for the preparation of amine functionalized polymer based on oligostyrene and its block copolymers. The oligo(St-co-VBC)s with controlled molecular weight were synthesized via nitroxide mediated polymerization method. We also successfully prepared organophilic layered silicates whose surface is covered with styrenic copolymers. Through the analysis of chemical structure and morphology, we concluded that copolymers were very effective organic modifiers to change the surface characteristics of layered silicates.

• Macromolecular Research
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• v.17 no.8
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• pp.557-562
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• 2009

The free radical polymerization of styrene was initiated with azobis(isobutyronitrile) in the presence of benzene sulfonyl chloride. Analysis of the terminal structures of the obtained polystyrene with $^1H$ NMR spectroscopy revealed the presence of a phenyl sulfonyl group at the ${\alpha}$-end and a chlorine atom at the ${\omega}$-end of each polystyrene chain. The terminal chlorine atom in the polystyrene chains was further confirmed through atom transfer radical polymerization (ATRP) of styrene and methyl acrylate using the obtained polystyrenes as macroinitiators and CuCl/2,2'-bipyridine as the catalyst system. GPC traces of the products obtained in ATRP at different reaction times were clearly shifted to higher molecular weight direction, indicating that nearly all the macroinitiator chains initiated ATRP of the second monomers. In addition, the number-average molecular weights of the polystyrenes increased directly proportional to the monomer conversions, and agreed well with the theoretical ones.

• Journal of Korea Foresty Energy
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• v.23 no.1
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• pp.45-68
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• 2004

The word of lignin is derived from the Latin word 'ligum' meaning wood. Lignin is complex polymer consisting of coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol unit and has an amorphous, three dimensional network structure which is hard to be hydrolyzed by acid. Lignin is found in the cell wall of plants lignified. The mode of polymerization of these alcohols in the cell wall lead to a heterogeneous branched and cross-linked polymer in which phenyl propane units are linked by carbon-carbon and carbon-oxygen bonds. This polymerization of precursors, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol to lignin is formed by enzymic dehydrolyzation. The reaction is initiated by an electron transfer which results in the formation of resonance-stabilized phenoxy radical. The combination of these radicals produces a variety of dimers, trimers and oligomers and so on. Lignin research has been divided into basic and practical application field. The basic studies contains biosynthesis, chemical structure, distribution in the cell wall and reactivity by reductants, oxidants and organic solvents. The application research will be approached the reaction of lignin in various pulp making involving pulp bleaching and its effect on pulp qualities. Lignin also will be studied for the production of fine chemicals, polymer products and the conservation into an energy source like petroleum oil because the amount of lignin produced in pulp making process is more than 51,000,000 tons per year in the world. Both basic and application research must lay emphasis on the development for the utilization of lignin and the pulping process. But these researches can not be completed without understanding lignin structure containing functional groups. Therefore, this paper was focused on the review of lignin formulation which has been studied since 1948 in chronological order. This review was based on monomers, dimers, trimers and tetramers of phenyl propane unit structures which were isolated and identified by different methods from various wood.ious wood.

• Polymer(Korea)
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• v.34 no.6
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• pp.517-521
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• 2010

Microprous polyethylene (PE) membranes are widely used as lithium-ion battery separators. A separator having higher meltdown temperature than PE separator is still required for useful safety feature at a high temperature. To enhance meltdown temperature of PE separator, it was coated with polymers synthesized from bis-GMA derivatives by radical polymerization. Polymer was not formed when bis-GMA monomer having a high viscosity was used, while polymers were formed when bis-GMA derivatives having a low viscosity were used. When the separator was coated with polymer synthesized from reaction mixture containing proper amount of bis-GMA derivative, its meltdown temperature were increased up to $160^{\circ}C$ without reduction in the air permeability.

• Journal of Information Display
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• v.11 no.3
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• pp.95-99
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• 2010

A series of new dielectric polymers with phenyl, epoxy, and carboxylicacid functional groups was prepared via free-radical polymerization. The effect of such dielectric polymers with various functional groups on the performance of OTFT was investigated. The nonpolar groups of terpolymer made the surface of the dielectric layer more hydrophobic and improved the crystal growth of pentacene on the gate insulator, resulting in higher mobility. By controlling the functional group, the electric characteristics of OTFT performance was varied, with $0.00017-0.15\;cm^2/V{\cdot}s$ mobility.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1809-1813
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• 2003

Monomeric antioxidant 1 was prepared by the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol with N-[4-(chlorocarbonyl)phenyl]maleimide in the presence of imidazole. Monomeric antioxidant 2, bearing carbamate group, was synthesized from the reaction of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol and azidomaleimide. Antioxidant 3 was prepared by the reaction of N-(4-hydroxyphenyl)maleimide and 3-(3,5-ditert-butyl-4-hydroxyphenyl) propionic chloride in the presence of triethylamine. These reactive antioxidants were grafted onto polypropylene (PP) by melt-processing with free radical initiators in a mini-max moulder. From the infrared spectra of the grafted PP, it was found that the monomeric antioxidants were grafted onto PP. IR spectroscopic methods were used for the quantitative determination of the extent of grafting of monomeric antioxidant. To optimize the reaction conditions, the influences of the concentration of DCP, monomeric antioxidant, reaction time and temperature on the extent of grafting were studied.