• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.644-647
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• 2000

The properties of hydrogen bonding between poly(2-ethyl-2-oxazoline)[PEOx] and poly(acrylic acid)[PAA] were investigated. PEOx and PAA formed stable complex and precipitated due to hydrogen bonding between hydrogen of PAA and oxygen of PEOx in acidic condition(below pH 4.3). Optimum reaction ratio of PEOx and PAA was determined as mass ratio of 1:1.5 for applications in aqueous two phase system. The mixtures of the polymers formed aqueous two phase system with dextran solution after the breakage of hydrogen bondings. This properties can be used for the recovery of valuable products.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.101-101
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• 2006

We have studied the micellisation of poly(n-butyl acrylate)-block-poly(acrylic acid) and poly(n-butyl acrylate)-graft-poly(acrylic acid) in aqueous solution. The size and structure of the formed micelles was elucidated by scattering and imaging techniques. The micelle structure depends on pH, composition, and topology: graft copolymers form much smaller micelles that block copolymers of similar composition. We have also synthesized block copolymers of acrylic acid and N-isopropylacrylamide (NIPAAm) or N,N-diethylacrylamide (DEAAm). Due to the LCST of polyNIPAAm and polyDEAAm, these block copolymers spontaneously form micelles upon heating and they form inverse micelles upon decreasing pH below 4. If the LCST block is much longer than the PAA one, this presents a very convenient way to prepare crew-cut micelles. The polymers have been successfully used as stabilizers in emulsion polymerization. They also have been conjugated to streptavidin. The conjugates reversibly form mesoscopic particles on heating.

• Membrane Journal
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• v.13 no.2
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• pp.118-124
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• 2003

The ion exchange membranes prepared from the reaction between poly(vinyl alcohol) (PVA) which is known as the good methanol barrier in pervaporation membrane processes and sulfo-succinic acid (SSA) was used as the basic membranes. In order to improve the ion exchange capacity, poly(acrylic acid) (PAA) was added to this ion exchange membranes. The methanol permeabilities, ion conductivities, water contents and ion exchange capacity were measured for the resulting membranes with varying PAA contents. In general, methanol permeability and ion conductivity of PVA/SSA/PAA membranes were less than those of PVA/SSA membranes due to the reduction of free volumes resulted from crosslinking. The vehicle mechanism could be more dominant than jump mechanism for membranes in question.

• Polymer(Korea)
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• v.33 no.1
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• pp.52-57
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• 2009

This study investigates the metal adsorption properties of poly (lactic acid)-g-acrylic acid (PLA-g- AAc) synthesized by UV irradiation method. The properties including degree of grafting, water content, and ion exchange capacity (IC) strongly depend on the critical experimental factors such as UV intensity and AAc concentration. Under the optimized condition, the maximum degree of grafting, the IC value, and water content are 28%, 1.13 meq/g, and 38%, respectively. The synthesized ion exchanger shows strong capacity of adsorption for divalent metal ions such as $Cu^{2+}$, $Ni^{2+}$, and $Co^{2+}$, and greater selectivity of adsorption for $Cu^{2+}$.

• Polymer(Korea)
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• v.32 no.6
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• pp.537-543
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• 2008

Crosslinked agar-g-poly(acrylic acid) (x-agar-g-PAA) super absorbent with a water absorbency ($Q_{H2O}$) of approximately 660 g/g was synthesized by the copolymerization of agar with an acrylic acid monomer. KPS and MBA were used as the initiator and crosslinker, respectively. Grafting was performed in air. Infrared spectroscopy was used to identify the product of copolymerization. The optimum conditions to synthesize the x-agar-g-PAA superabsorbent were 0.1 g of agar, 0.1 g of the KPS initiator, for 15 min; 50% AA monomer, 0.005 g of the MBA crosslinker, for a propagation time of 5 min; and 1 M NaOH for 15 min to allow for saponification. The reaction temperature was $80{^\circ}C$.

• Journal of Adhesion and Interface
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• v.13 no.3
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• pp.109-115
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• 2012

Monodisperse blue-colored poly(styrene-co-acrylic acid) latices were successfully prepared by seeded emulsion polymerization. Blue-colored latices with carboxyl anionic charge on the surface were synthesized at the second stage with the introduction of Blue 606 dye, acrylic acid, and 0.21 ${\mu}m$-polystyrene seed. All the blue-colored latices synthesized in this study were in the size range of 0.25~0.42 ${\mu}m$ and all uniform with less than 1.01 in PSD. The particle size increased with the addition of acrylic acid being delayed and colloidally stable latices were obtained over 30 min after its addition. The blue-colored latex with 20 wt% acrylic acid showed -145 mV of zeta-potential and $-9.4{\times}10^{-6}\;cm^2/Vs$ of electrophoretic mobility, and with 25 wt% of DVB showed high $T_g$ at 396.7 K.

• Membrane Journal
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• v.12 no.4
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• pp.255-261
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• 2002

Poly(vinyl alcohol) (PVA) membranes crosslinked with poly(acrylic acid-co-maleic anhydride) (PAM) as a polymeric crosslinking agent were prepared to investigate the pervaporation performance for the dehydration separation of aqueous ethanol solution. The characteristics of the resulting membranes crosslinked(x) were analysed by FT-IR and water swelling test. The water swelling decreased with increasing crosslinking agent content. The crosslinked PVA membranes with PAM showed lower water swelling than those of PVA membrane crosslinked with glutaraldehyde and modified PVA membrane. The swelling of water molecules in the crosslinked PVA membranes is more restricted by both chemical crosslinking between PVA and polymeric crosslinking agent chains and physical crosslinking by the entanglement between the PVA and polymeric crosslinking agent chains. For the pervaporation of aqueous ethanol solution through the crosslinked membrane, as the contents of crosslinking agent increased, the separation factor increased while the permeation flux decreased. The separation factor slightly decreased and permeation flux increased with increasing feed water content. As a result it could be considered that PVA-PAM membranes suppressed the plasticization effect even in the range of high water concentration in fled.

• Polymer(Korea)
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• v.34 no.2
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• pp.150-153
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• 2010

In this research, biomolecule-immobilized multi-walled carbon nanotubes (MWCNTs) were prepared by using radiation-induced graft polymerization. For the immobilization of biomolecules, the surface of MWNCTs was functionalized by radiation-induced graft polymerization of acrylic acid. Based on the results of TGA and Raman spectroscopy it was found that acrylic acid was effectively graft-polymerized on the MWCNTs. Biomolecules such as DNA and proteins were immobilized onto the resultant poly(acrylic acid)-grafted MWCNTs. The results of the X-ray photoelectron spectroscopy and fluorescence microscopy confirmed that the biomoelcules were successfully immobilized on the poly(acrylic acid)-grafted MWCNTs.

• Polymer(Korea)
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• v.25 no.1
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• pp.90-97
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• 2001

Dispersions are prepared from poly(ethylene-co-acrylic acid) (PEAA) ionomer with two different counter-ions, ammonium and sodium. The diffusional characteristic of urea aqueous solution are measured for the films prepared from the above mentioned dispersions. It is attempted to find the relationship between diffusional behavior and various chemical and physical characteristics of films. DSC is employed to characterize glass transition temperature and degree of crystallinity and the structural features of crystal phase and ionic clusters are examined by WAXD and FTIR. The diffusional characteristics of ionomer is found to be dependent on various parameters such as the size of initial dispersion as well as the kind of counter ion and the degree of neutralization.

• Journal of Radiation Industry
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• v.9 no.2
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• pp.77-84
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• 2015

The stainless steel mesh coated with poly(acrylic acid) hydrogel was fabricated and applied for the separation of water and oil. The stainless steel mesh was immersed in aqueous poly (acrylic acid) solution, and then irradiated by radiation to introduce poly(acrylic acid) hydrogel on the surface of mesh by crosslinking. It was possible to separate oil and water from mixtures of oil/water effectively using the hydrogel-coated mesh. The effect of irradiation dose, coating thickness, size of mesh on the separation efficiency was examined.