• Polymer(Korea)
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• v.36 no.2
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• pp.137-144
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• 2012

The surface of polyethylene (PE) was modified through Ar atmospheric pressure plasma treatment and subsequent grafting of glycidyl methacrylate (GMA). Optimum plasma treatment conditions were determined through analyzing the surface free energies calculated from the contact angles between PE samples and three probe liquids, which were RF-power of 200 W, plasma treatment time of 600 sec, Ar flow rate of 5 LPM, and sample-holder moving speed of 20 mm/sec. To introduce the maximum amount of GMA on PE surface treated under the conditions, graft copolymerization conditions such as GMA concentration, temperature, and time were carefully controlled. Grafting degree (GD) was obtained through weight difference analysis of PE film before and after graft copolymerization. A maximum GD was achieved at the GMA concentration of 20 vol%, the temperature of $80^{\circ}C$, and the treatment time of 4 hr.

• Polymer(Korea)
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• v.36 no.1
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• pp.65-70
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• 2012

Glycidyl methacrylate (GMA) was used to introduce epoxy groups on the surface of polypropylene (PP) plate, used as a substrate, through plasma-induced graft copolymerization. Emulsion polymerization was applied for graft copolymerization of GMA and was compared with conventional solution polymerization to confirm its effect. Plasma treatment conditions under one atmospheric pressure were fixed as follows; the RF power of 200 W, the treatment time of 30 sec, the Ar gas flow rate of 6 LPM, and the exposure time of treated PP samples in air of 5 min. For graft-copolymerization, GMA concentration, reaction temperature, and reaction time was optimized to maximize the grafting degree of GMA. The maximum grafting degree of GMA was obtained at the condition of 12%-GMA concentration, $90^{\circ}C$ reaction temperature, and 5 hr-reaction time. Analysis results supported that the emulsion polymerization was more effective than the solution polymerization for grafting more GMAs on the surface of PP plate under the same reaction conditions.

• Applied Chemistry for Engineering
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• v.20 no.3
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• pp.339-345
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• 2009

The graft copolymerization of acrylonitrile-EPDM-styrene (AES) was investigated under various reaction conditions such as the concentration of initiator, the content of diene and viscosity of EPDM, and the concentration of solvents. The conversion increased but the molecular weight and the rubber particle size decreased with the concentration of initiator. The graft ratio(GR) increased at low concentrations of the initiator but, after the maximum value, it gradually decreased with the concentration of initiator. Toluene as a single solvent gave the highest conversion and the mixture of ethyl benzene and toluene was better than toluene. The rubber particle size increased with the viscosity of EPDM and the graft ratio and the number of rubber particles with occluded SANs increased with the content of diene.

• Elastomers and Composites
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• v.43 no.4
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• pp.221-229
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• 2008

Starch as matrix polymer was used to do graft copolymerization with 2-ethylhexylacrylate, methyl methacrylate and acrylic acid. The polymerization was carried out by radical emulsion polymerization with increasing contents of starch. When 0.174% of $\alpha$-amylase as enzyme for starch was added, it was found that it made the best stable emulsion. The glass transion temperature of the polymerized material was increased with starch contents. The particle size and viscosity of the emulsion increased with starch contents due to the increased hydroxy group. Peel strength also increased with contents of starch because the enhanced hydroxy group caused to increase affinity between substrate surface and polymer materials. However, the initial tackiness decreased with starch contents owing to film hardness by higher glass transion temperature.

• Journal of the Korean Chemical Society
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• v.20 no.4
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• pp.309-315
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• 1976

An efficient separation method and the utilization of sericin are searched. Sericin was extracted with hot water from cocoons under atmospheric pressure. The separated sericin was gel-filtrated with Sephadex G-75 and G-150 at room temperature and at $70^{\circ}C$. The results indicated that sericin is consisted of only one fraction in elution diagram. In the graft copolymerization of acrylonitrile to sericin ceric ammonium nitrate was chosen as an initiatior. A maximum yield was obtained at certain concentration of the initiator confirming our previous experiments. Viscosity measurement of alkali-hydrolyzed graft copolymers indicated that the polyacrylonitrile graft had the molecular weight in the range of 7,000.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.83-92
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• 1999

Chitosan was prepared from chitin which was abstracted from wasted crab shells. Then itaconic acid was graft-copolymerized onto chitosan using ceric ammonium nitrate as a reaction initiator. To investigate the optimal grafting conditions, the influences of several factors on the grafting were studied, i. e., the concentrations of CAN and itaconic acid, the reaction temperature and time. And to find out its flocculation ability. the flocculation test was carried out with a metal plating factory waste water. The state of graft-copolymer was identified through IR spectra analysis. The optimal grafting conditions and flocculation results were shown to be : concentration of ceric ammonium nitrate is $3.5{\times}10^3M$, reaction temperature is $40^{\circ}C$ and reaction time is 4hrs with 0.25M of the monomer(itaconic acid). Though flocculation tests using chitosan, grafted chitosan and cation, CODcr. metal ions removal rates were measured. The order of superiority is Itaconic acid grafted chitosan>Chitosan>Cationic polymer.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.698-705
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• 1994

The basic medium oil modified alkyd resin was synthesized from linseed oil fatty acid(LOFA), phthalic anhydride(PAA), maleic anhydride(MA) and trimethylol propane(TMP) by condensation polymerization at $230^{\circ}C$. MA/TMPTA modified water-reducible alkyd resins were synthesized with TMPTA graft copolymerization onto the basic resin at $180^{\circ}C$. Acid value of the resin was controlled by the addition amount of MA and N,N-dimethylethanol amine(DMEA) was used as a neutralizing agent to prepare of the water-reducible alkyd resin. The effect of TMPTA on the graft copolymerization of the resin was studied by measuring molecular weight glass transition temperature(Tg), viscosity, graft efficiency, and gel contents of melanin cured film. Heat resistance, UV resistance and water resistance of cured film of MA/TMPTA modified resin was compared to those of TMA/TMPTA modified alkyd resin. The molecular weight, viscosity gel contents and graft efficiency of water reducible alkyd resin were increased according to the TMPTA graft copolymerization, but Tg was decreased. The viscosity was lower when the solid contents reached 40% than that of 30% content and also and also became lower with the extent of neutralization ratio, The heat resistance, UV resistance and water resistance of the MA/TMPTA modified alkyd resis were better than those of TMA/TMPTA modified alkyd resin but the storage stability of the TMA/TMPTA alkyd resis was better than that of MA/TMPTA modified alkyd resin.

• Proceedings of the Korean Fiber Society Conference
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• 1987.06a
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• pp.67-67
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• 1987

• Polymer Science and Technology
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• v.3 no.6
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• pp.481-488
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• 1992

• Proceedings of the Korean Fiber Society Conference
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• 1988.06a
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• pp.6-7
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• 1988