• 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.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.603-608
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• 2005

The molded macroporous poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) rods produced by a facile molding process were polymerized in situ within a tubular mold, chromatographic column ($4.6{\times}100mm$) by free radical polymerization. It was complemented by epoxy derivatized monolithic column and chemical modification of the epoxide groups with the sulphuric acid. By variation of the polymerization conditions, such as the ratio of the monomers, the porogen (pore generating material), and the temperature, the pore size could be varied, so the retention time of the samples may be adjusted. For the mixture of caffeine and tryptophan in the prepared monolithic column, the influences of polymerization material compositions to the efficiency, selectivity, and resolution of the monolithic column were investigated.

• Carbon letters
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• v.11 no.1
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• pp.22-27
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• 2010

The precipitation polymerization of acrylonitrile (AN) was carried out in a mixture solution of dimethyl sulfoxide (DMSO) and water at $50{\sim}65^{\circ}C$ using ${\alpha},{\alpha}'$-azobisisobutyronitrile (AIBN) as an initiator. The increased molecular weight polyacrylonitrile (PAN) was prepared with increasing the $H_2O$/DMSO ratio from 10/90 to 80/20. The viscosity average molecular weight of $H_2O$/DMSO solvent was 4.4 times larger than that of $H_2O$/DMF solvent, and precipitation polymerization was accelerlated due to the far decreased chain transfer effect of DMSO. Based on the experimental results, the increased PAN molecular weight was regarded as the summation of two mechanisms: i) particle-particle aggregation and ii) particle-radical attachment. The theoretical equation derived from the mechanisms was well coincided with the experimental results showing the linear relationship between the viscosity average molecular weight and the H2O/DMSO ratio.

• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1609-1612
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• 2003

The electrooxidation of 8-(3-acetylimino-6-methyl 2,4-dioxopyran)-1-aminonaphthaline (AMDAN) in aqueous and non aqueous media led to the formation of polymeric films, poly (AMDAN). The monomer, undergo anodic oxidation through the formation of a monocation radical irrespective of the nature of the medium. In aqueous medium, the monocation radical undergoes, through its resonance structures, dimerisation involving tail-to-tail, head-to-tail and even head-to-head coupling. The products formed, being more easily oxidisable than the parent substance, undergo further oxidation at the same potential so that the overall oxidation involves a one-step (i.e., a single wave), two-electron process. In non-aqueous medium, the monocation radical does not undergo dimerisation through coupling reactions. Retaining its identity, monomer oxidise in two steps involving one electron in each step. The fact that the cathodic peaks corresponding to these anodic peaks are rarely observed indicates fast consumption of the electrogenerated monocation radicals and dications by follow-up chemical reactions to produce polymeric products (poly AMDAN). The electrochemical behavior of the formed polymer films was investigated in both non aqueous and aqueous media. The films prepared in non aqueous medium were found to be more electroactive than that the films prepared in aqueous medium. This is confirmed with the results in litreature which illustrate that the film prepared in aqueous solution hold water in its structure via hydrogen bonding, which causes decomposition reactions.

• Journal of Adhesion and Interface
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• v.11 no.4
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• pp.174-180
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• 2010

The effect of carbon nanotube surface treatment on the interface and thermal conductivity of carbon nanotube-based poly(methylmethacrylate) (PMMA) composites was investigated. Coagulation and atomic-transfer radical polymerization (ATRP) was applied to modify the surface of multi-wall carbon nano-tube. The composite of ATRP method used carbon nanotube showed the higher transparency and thermal conductivities than that of the coagulation method used. In comparison to the thermal conductivity of pure PMMA, 0.21 W/mK, the ATRP carbon nanotube used PMMA/MWNT composite showed a thermal conductivity of 0.38 W/mK. The interface between carbon nanotube and PMMA was observed by scanning electron microscope and uniform dispersion of carbon nanotube was observed without any void in the PMMA matrix. It may be beneficial to transport the phonon without any scattering and it may result in a higher thermal conductivity.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.80-85
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• 1980

The free radical copolymeriaztion of N-vinylurea(VU) with vinyl acetate (VAc) was carried out at $60^{\circ}C$ in three solvents. VU-vinyl alcohol(VA) copolymers were prepared by the methanolysis of the VU-VAc copolymers. From the nitrogen content measurements of VU-VA copolymers, the monomer reactivity ratios for the VU-VAc copolymerization and the values of Alfrey-Price's Q and e for VU were determined. These Q and $\varrho$ values obtained in the cases of using methanol and methanol-dioxane as the polymerization solvents are comparable with those found for other monomers which have > NCO-pendent groups. The $\varrho$ value indicates that the urea group of VU is a electron-donating group. The copolymerization parameter of VU shows a strong effect of the solvents. These results are interpreted to be that VU is in equilibrium with its tautomer at the polymerization temperature.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.579-585
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• 2017

Acrylic resins containing tertiary amine were synthesized by a radical polymerization of monomers including n-butyl acrylate (BA), methyl methacrylate (MMA), n-butyl methacrylate (BMA) and dimethylaminoethyl methacrylate (DMAEMA), and diethylaminoethyl methacrylate (DEAEMA) containing tertiary amine. Synthesized acrylic resins were applied to develope coatings of acrylic resins containing tertiary amine. And ${\gamma}$-glycidoxypropyl trimethoxysilane (GPTMS) or ${\gamma}$-glycidoxypropyl triethoxysilane (GPTES) was used as hardener. Developed coatings were white colored ones to use titanium dioxide and were hardened with hardener for measuring their physical properties. Measured physical properties were basic properties, adhesivity and weatherability. As a result, developed acrylic resins coatings containing tertiary amine showed excellent adhesivity on various substrates and also showed the same result on weatherability on dry weather condition.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.415-422
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• 2009

In this study, several factors were analyzed in an effort to determine the effects of transglutaminase (TGase) treatment on sodium caseinate (NaCN), ${\alpha}--lactalbumin$ (${\alpha}-La$), and ${\beta}-lactoglobulin$ (${\beta}-Lg$) polymerization reactions. The results of SDSPAGE showed that NaCN was slightly hydrolyzed to molecular weights of 50-400 kDa according to activation time. ${\alpha}-La$ formed high-molecular polymers of 30-300 kDa, whereas ${\beta}-Lg$ remained almost completely unhydrolyzed. Melting temperatures of NaCN, ${\alpha}-La$ with and without TGase were all in the range of $100{\pm}10^{\circ}C$ under the endothermic curve, and the melting temperature of ${\beta}-Lg$ with TGase was lower than that with TGase. When the proteins were incubated for 3 h with TGase, the micrographic structures showed a small quantity of sediment and broad layers. The final ${\alpha}-La$ residues remained at a level of 21.38%, and the TGase-treated ${\alpha}-La$ was confirmed to have undergone a profound loss of mass, to 18.25%. The DPPH-radical scavenging activity of NaCN and ${\beta}-Lg$ with TGase treatment was higher than that observed in the untreated sample, while those of ${\alpha}-La$ increased with concentration.

• Membrane Journal
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• v.20 no.1
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• pp.1-7
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• 2010

A graft copolymer, i.e. poly(vinylidene fluoride-co-chlorotrifluoroethylene )-g-poly(styrene sulfonic acid) (P(VDF-co-CTFE)-g-PSSA) with 47 wt% of PSSA was synthesized via atom transfer radical polymerization (ATRP). This copolymer was combined with titanium isopropoxide (TTIP) to produce graft copolymer/$TiO_2$ nanocomposite membranes via sol-gel process. $TiO_2$ precursor (TTIP) was selectively incorporated into the hydrophilic PSSA domains of the graft copolymer and grown to form $TiO_2$ nanoparticles, as confirmed by FT-IR and UV-visible spectroscopy. Water uptake and ion exchange capacity (IEC) decreased with TTIP contents due to the decrease in number of sulfonic acid in the membranes. At 5 wt% of TTIP, the mechanical properties of membranes increased while maintaining the proton conductivity.

• Membrane Journal
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• v.20 no.1
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• pp.55-61
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• 2010

A diblock copolymer of polystyrene-b-poly(oxyethylene methacrylate) (PS-b-POEM) was synthesized via atom transfer radical polymerization (ATRP), as revealed by FT-IR spectroscopy. The self-assembled block copolymer membrane was prepared and used to template the growth of silver nanoparticles in the solid state by the introduction of $AgCF_3SO_3$ precursor and UV irradiation process. Transmission electron microscopy (TEM) and UV-visible spectroscopy confirmed the in situ formation of silver nanoparticles within the block copolymer membranes, and the size of nanoparticles were controlled by adjusting the moiety of hydrophilic POEM domains. PS-b-POEM block copolymer with a lower POEM content was effective in generating smaller size of metal nanoparticles.