• Journal of Integrative Natural Science
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• v.5 no.2
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• pp.127-130
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• 2012

Polymerization of vinyl monomers is promoted by thianthrene cation radical as a part of our research concerning the reactions of various agents with readily isolable, yet highly reactive species and elucidate the biological activity. Thianthrene cation radical initiated the homopolymerization and copolymerization of styrene and ethyl vinyl ether. The polymerization yields decreased as the concentration of phenylacetylene or diphenylethylene increased. Such polymereization by cationic thianthrene radical could provide some clues for the reaction in living animals. Comments on possible polymerization mechanisms were suggested.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.48-51
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• 2002

In order to study the reaction behavior of bovine holo- and apo-$\alpha$-lactalbumin ($\alpha$-La) during heat treatment at 65~10$0^{\circ}C$, the samples were analysed by first (ID)-and second-dimensional (2D) native-polyacrylamide gel electrophoresis (Native-PAGE) and sodium dodecylsulfate (SDS)-PAGE. When bolo-$\alpha$-La or apo- $\alpha$ -La were heated, they formed non-native, monomers, dimers and trimers. The apo-$\alpha$-La was more heat-sensitive than holo-$\alpha$-La. The monomers seemed to have the same composition as the native $\alpha$-La, but many of the disulfide bonds could be non-native.

• Bulletin of the Korean Chemical Society
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• v.25 no.11
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• pp.1648-1652
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• 2004

A set of unprecedented syndiospecific dimethyl- and diethylamino-functionalized polystyrenes was prepared by catalytically polymerizing the corresponding monomers using (pentamethylcyclopentadienyl)titanatrane/MMAO catalytic system. Dialkylamino-functionalized styrene monomers were synthesized by Wittig reaction from the corresponding aldehyde in high yield. The resulting polymers are soluble in polar organic solvents such as THF and show good thermal stability. The chemical transformation of the syndiospecific poly(4-diethylaminostyrene) also gave new polar polymers, namely syndiotactic poly(4-diethylaminostyrene hydrochloride), which is unattainable by traditional synthetic methods.

• Macromolecular Research
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• v.14 no.3
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• pp.324-330
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• 2006

Four different molecularly imprinted polymers (MIPs) were prepared using resveratrol as the template, methacrylic acid (MAA) or acrylamide (AA) as functional monomers, 2,2-azobisisobutyronitrile (AIBN) as the initiator, and thermo- or photo-induced polymerization. The ability of the different polymers to rebind selectively not only the template but also other phenols was evaluated. In parallel, the influence of the different templates and functional monomers used during polymer syntheses on the performance of the obtained MIPs was also studied through different rebinding experiments. The binding ability and selectivity of the polymer were studied by static balance method and Scatchard analysis. It was concluded that AA-based polymer by photo-induced polymerization presents the best properties to be used as a selective absorbent for the extraction of resveratrol.

• Journal of Integrative Natural Science
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• v.6 no.2
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• pp.71-75
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• 2013

$Bu_3Sn$-endded poly(vinyl)s with biological activity were obtained by the radical polymerization of vinyl monomers using thianthrene cation radical/$^nBu_3H$. Thianthrene cation and stannyl radicals promoted the homopolymerization and copolymerization of styrene and ethyl vinyl ether having number average molecular weights of 2000-3100. Tributyltin hydride functions as a chain transfer agent. Such polymereization by cationic thianthrene and stannyl radicals could provide some clues for the biological reaction in living animals. Plausible polymerization mechanisms were suggested.

• Proceedings of the Korean Fiber Society Conference
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• 1996.10a
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• pp.53-58
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• 1996

The Chitin Thiocarbonate-Fe(II)-H2O2 redox initiator system was investigated for the graft copolymerization of acrylonitrile(AN) and acrylic acid(AA) monomers onto chitin powder. The reactions with vinyl monomers onto chitin were carried out under various the graft copolymerization conditions to elucidate the polymerization behavior in terms of graft yield. Reactions of chitin-acrylonitrile graft copolymer with hydroxyl amine hydrochloride and those with sodium hydroxide were conducted in order to obtain chitin-(amidoxime-co-acrylonitrile) and chitin-(acrylate-co-acrylamide) graft copolymers, respectively. The reaction efficiency was observed to depend on the alkali concentration, time, temperature, and the reactant concentrations. The prepared chitin derivatives were evaluated to find potential applications for use in wastewater treatments for adsorption and desorption of heavy metal ions as well as acidic and basic dyes.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.561-562
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• 2003

pH varies in the oral environment and on tooth surfaces. The surface of a plaque covered resinous restoration has a low pH. In human dental plaque a number of acids are produced by bacterial metabolism. The predominant acids are acetic, propionic and lactic acids. These acids induced a surface swelling of restorative resin. The swelling cause formation of pores inside the resin matrix from which organic substances can be released, resulting in a mass loss. The purpose of this study was to qualitatively and quantitatively analyse the leached monomers of dental composites after storage in acetate buffer solution as a function of time by means of high performance liquid chromatography(HPLC) / mass spectrometer and further determine whether pH and time has any influence on the degradation behavior of composite restoration.(omitted)

• Bulletin of the Korean Chemical Society
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• v.6 no.3
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• pp.128-131
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• 1985

A series of copolymer membranes of 2-hydroxyethylmethacrylate (HEMA) with selected hydrophobic monomers were prepared without crosslinking agents. The equilibrium water content, the partition coefficient, and the permeability of the solutes such as urea, methylurea, 1,3-di-methylurea, and acetamide via these membranes were measured. The partition coefficient data show that as the hydrophobicity of solutes increased, the partition of solutes were dictated by hydrophobic interaction between solute and polymer matrix. Diffusion coefficients obtained in these experiments decrease as the water content of polymer membrane decreases. This decrease is blunt as the excess heat capacities, ${\phi}C^0_p$ (excess) in aqueous solution at infinite dilution of solute increases. To investigate the relationship between water content and diffusion coefficient, the results of the diffusion experiments were examined in light of a free-volume model of diffusive transport. The remarkable increase of urea mobility in the polymer network containing relatively larger bulk water can be considered as water structure breaking effect.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.328-333
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• 1997

Dicyanovinyl-containing bis-hydroxy monomers, p-bis[1-(4-hydroxypiperidinyl)]-2,2-dicyanovinyl]benzene (2), p-bis[1-[1-(2-hydroxyethyl)piperazinyl]-2,2-dicyanovinyl]benzene (3), p-bis[1-(4-hydroxyphenylamino)-2,2-dicyanovinyl]benzene (4) and p-bis[1-[N-methyl-(N-hydroxyethyl)amino]]-2,2-dicyanovinyl]benzene (5) were prepared from p-bis(1-chloro-2,2-dicyanovinyl)benzene (1) and the corresponding amino alcohol. The poly(enaminonitriles-ester)s with a variety of chemical structures in the main chain were prepared from them. The chemical structure of polymers was confirmed through the syntheses of their corresponding model compounds. The polymers are easily soluble in polar aprotic solvents such as DMF, DMSO and NMP. Brittle and hard films can be cast from DMF solutions of polymers. Most polymers showed a large exotherm in DSC analyses and undergo a curing reaction around 350 ℃ to form insoluble materials. The polymers consisting of rigid aromatic moieties show 80-88% residual weight at 500 ℃ under nitrogen.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.563-563
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• 2003