• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.700-703
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• 2010

• Safe Food
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• v.6 no.2
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• pp.34-39
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• 2011

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.717-718
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• 2013

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2003.11a
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• pp.58-60
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• 2003

• Macromolecular Research
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• v.8 no.1
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• pp.26-33
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• 2000

A series of pH/temperature sensitive polymers were synthesized by copolymerizing N-isopro-pyl acrylamide(NIPAAm) and acrylic acid(AAc) . The influence of polyelectrolyte between poly(allyl amine) (PAA) and poly(L-lysine)(PLL) on the lower critical solution temperature(LCST) of pH/temperature sensitive polymer was compared in the range of pH 2∼12. The LCST of PNIPAAm/water in aqueous poly(NIPAAm-co-AAc) solution was determined by cloud point measurements. A polyelectrolyte complex was prepared by mixing poly(NIPAAm-co-AAc) with poly(allyl amine) (PAA) or poly(L-lysine) (PLL) solutions as anionic and cationic polyelectrolytes, respectively. The effect of polyelectrolyte complex formation on the conformation of PLL was studied as a function of temperature by means of circular dichroism(CD). The cloud points of PNIPAAm in the aqueous copolymers solutions were stongly affected by pH, the presence of polyelectrolyte solute, AAc content, and charge density. The polyelectrolyte complex was formed at neutral condition. The influence of more hydrophobic PLL as a polyelectrolyte on the cloud point of PNIPAAm in the aqueous copolymer solution was stronger than that of poly(allyl amine)(PAA). Although polymer-polymer complex was formed between poly(NIPAAm-co-AAc) and PLL, the conformational change of PLL did not occur due to steric hinderance of bulky N-isopropyl groups of PNIPAAm.

• Polymer(Korea)
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• v.28 no.1
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• pp.18-23
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• 2004

Superabsorbent poly(potassium acrylate-co-acrylamide)s were synthesized in particle form using inverse suspension polymerization technique. Mean diameter of the prepared polymer particles decreased from 300 to 50 $\mu\textrm{m}$ with increasing surfactant concentration. The dynamic and equilibrium swelling behaviors during water absorption and drying process were investigated by weight measurement. The swelling ratio of polymer particles in water changed according to not only polymer crosslinking density, but particle size, saline concentration of aqueous medium, and copolymer compositions. Water sorption amount was increased with decreasing particle size, crosslinking agent concentration, and ion concentration in bulk solution. Being different from the water sorption process, the drying process was not significantly affected by particle size, polymer composition, or crosslinking amount.

• Journal of the Korean Chemical Society
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• v.42 no.2
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• pp.156-160
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• 1998

Probe diffusion with latex particles in two different types of chemically cross linked gel has been studied. The diffusion of particles in silica gel is decreased by decreasing the gel correlation length but the particles' diffusion in the acrylamide gel still shows the heterogeneity of the gel. By increasing the contents of the gel network the silica gel makes a more homogeneous and compact structure than that of acrylamide gel which has partial heterodyning. Dynamic light scattering study with the probe particles in two different gels reveals the heterogeneity of the gel network. The latex particles trapping in the gel has been investigated by using non-ergodic concepts.

• Carbon letters
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• v.14 no.1
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• pp.34-39
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• 2013

Acrylonitrile (AN)-acrylamide (AM) copolymers were prepared by nitric acidic hydrolysis of homopolyacrylonitrile. The acrylamino group increased as a function of hydrolysis time, while crystallinity decreased. Differential scanning calorimetry and a thermal gravimetric analysis indicated that the acylamino introduced by acidic hydrolysis effectively enhanced the cyclization reaction at low temperature due to the change of the cyclization reaction mechanism. Char-yield of AN-AM copolymers also gradually increased with increasing hydrolysis time. The maximum char-yield was 49.48% when hydrolized at $23^{\circ}C$ in 65% nitric acid solution for 18 h, which was 30% higher than that of non-acidic hydrolysis of homopolyacrylonitrile. Simulation of the practical process also showed an increase of char yields, where the char yields were 55.43% and 62.60% for homopolyacrylonitrile and copolyacrylonitrile, respectively, with a hydrolysis time of 13 h.

• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.1-7
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• 1989

To developed new process for obtaining maximum molecular weight of anionic acrylamide and acrylic acid copolymer by inverse emulsion polymerization. Concentration of initiator, reducing agent, surfactant and mole ratio of acrylamide-acrylic acid were studied for the process. Semi-batch processes with method of redox, control of reaction temperature, feeding method of monomer and reaction time, was suitable for maximum molecular weight of P(AMAC) from this process obtained $3.09\;{\time}\;10^6({\bar{M}}n.)$ and $4.41\;{\time}\;10^6({\bar{M}}w.)$ in molecular weight measured by the intrinsic viscosity method. inverse emulsion polymerization mechanism of P(AMAC) does not followed the Smith-Ewart and Medvedev theory, but selected for concentration of initiator, reducing agent, surfactant, water solubility of monomer.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.3
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• pp.47-53
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• 1998

Using Michael Reaction, commercially available 3-aminopropyltrimethoxysilane and N-[3-(trimethoxysilyl)propuyl]ethylenediamine were reacted with various Michael acceptors, ethyl acrylate, acrylonitrile, acrylamide, 2-cyanoethyl acrylate, 2-hydroxyethyl acrylate and 3-(trimethoxysilyl)propylmethacrylate, to the new aminosilanes. All compounds which are [3-(N-2-carboethoxyethyl)aminopropyl]triethoxysilane, [3-(N-2-cyanoethyl)aminopropyl]triethoxysilane, [3-(N-di-2-car-boethoxyethyl)aminopropyl]triethoxysilane, [3-N-di-cyanoethyl) aminopropyl]triethoxysilane, [3-(N-2-cyanoethoxypropionyl)aminopropyl]triethoxysilane, [3-(N-di-2-cyanoethoxypropionyl)aminopropyl]triethoxysilane, [3-(N-di-2-hydroxyethoxy propionyl)aminopropyl]triethoxysilane, [3-(N-2-amidoethyl)aminopropyl]triethoxysil-ane,｛3-[N-(N-di-2-cyanoethyl)ethyl]aminopropyl｝triethoxysilane and ｛3-[N-(3-trimethoxysilylpropyl)-2-methylpropionyl]aminopropyl｝triethoxysilane were succes-sfully prepared in 35-70% yields and which were identified with $^1{H}$-NMR and FT-IR spectroscopy.