• Polymer(Korea)
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• v.28 no.6
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• pp.487-493
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• 2004

The distribution of particles, in the mixture of poly(ethyl acrylate-co-t-butyl acrylate) (PEB) emulsion polymer and silica nanoparticles, was determined mainly depending on the pH of the mixture. The weak interfacial interaction was responsible for the severe coagulation of silica particles and the irregular dispersion for these nanocomposites. Methacryloxypropyltrimethoxysilane (MPS) was used to modify both the polymer and the silica. The nanocomposites which were prepared with these modified components had finer dispersion of silica nanoparticles and core-shell morphology due to the strong interfacial interaction. The strong hydrogen bonds were identified for these nanocomposites with FT-IR. The nanocomposites having strong interfacial interaction showed the increased glass transition temperature, the decreased ΔC$_{p}$ , and the increased decomposition temperature of the polymer chains. polymer chains.

• Macromolecular Research
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• v.16 no.6
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• pp.555-560
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• 2008

A series of hydroxyl-group containing polyimides (HPIs) were prepared in order to investigate the structure-gas permeation property relationship. Each polymer membrane had structural characteristics that varied according to the dianhydride monomers. The imidization processes were monitored using spectroscopic and thermog-ravimetric analyses. The single gas permeability of He, $H_2$, $CO_2$, $O_2$, $N_2$ and $CH_4$ were measured and compared in order to determine the effect of the polymer structure and functional -OH groups on the gas transport properties. Surprisingly, the ideal selectivity of $CO_2/CH_4$ and $H_2/CH_4$ increased with increasing level of -OH incorporation, which affected the diffusion of $H_2$ or the solubility of $CO_2$ in HPIs. For $H_2/CH_4$ separation, the difference in the diffusion coefficients of $H_2$ and $CH_4$ was the main factor for improving the performance without showing any changes in the solubility coefficients. However, the solubility coefficient of $CO_2$ in the HPIs increased at least four fold compared with the conventional polyimide membranes depending on the polymer structures. Based on these results, the polymer membranes modified with -OH groups in the polymer backbone showed favorable gas permeation and separation performance.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.125-134
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• 2010

This study was performed to evaluate the workability, strengths and durability of polymer concrete using oyster shell that are reclaimed at public shore illegally or leaved on the surroundings of shore to prevent the environmental pollution. We investigated the effect of oyster shell powder (OSP) and $CaCO_3$. on the slump, compressive strength, flexural strength, acid sulfuric and freezing and thawing resistance as a filler of polymer concrete. Modified OSP obtained by crushing oyster shell (less than 0.15 mm size) consists of 60.47 wt% of $SiO_2$ and 39.5 wt% of $CaCO_3$. As a result of slump test by OSP and $CaCO_3$. contents, it is found that slump of specimen used OSP is lower than that used $CaCO_3$. and the more OSP contents are, its slump is increased. Compressive and flexural strength of polymer concrete using OSP are similar or slightly lower than that using $CaCO_3$. In acid sulfuric test for 5 % $H_2SO_4$ and freezing thawing test, regardless of kinds of fillers and contents are not found fatal defects in weight change, falling-off in surface and durability factor.

• Polymer Science and Technology
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• v.4 no.1
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• pp.57-66
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• 1993

• Journal of the Korean Applied Science and Technology
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• v.13 no.2
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• pp.77-84
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• 1996

Poly(vinyl acetate)와 poly(vinyl acetate-co-2-ethylhexyl acrylate)를 여러 조건에서 semicontinuous emulsion 중합으로 합성하였다. Overall conversion, emulsion 입자크기, pH, 점도 등을 합성한 두 emulsion polymer에 대해 측정하였다. Vinyl acetate monomer에 2-ethylhexyl acrylate를 도입함으로서 emulsion 입도, 점도, 중합 속도, 유리 전이 속도가 감소함을 확인하였다.

• Polymer Science and Technology
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• v.4 no.2
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• pp.124-132
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• 1993

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.136-145
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• 1994

Polymeric complexes such as M(Ⅱ)(PVPS)(SND), M(Ⅱ)(PVPS)(SOPD) have been prepared with monomeric complexes, M(Ⅱ)(SND) and M(Ⅱ)(SOPD)[M: Co(Ⅱ), Ni(Ⅱ), and Cu(Ⅱ)] and polymer PVPS. These complexes have been indentified by elemental analysis, spectroscopy, and T.G.A. From the results, it was found that M(Ⅱ)(PVPS)(SND), M(Ⅱ)(PVPS)(SOPD) complexes were penta-coordinated configuration. Electrochemical properties of these complexes studied by cyclic voltammetry and differential pulse polarography in 0.1 M TEAP-DMF solution at glassy carbon electrode. Co(Ⅱ)(PVPS)(SND) and Co(Ⅱ)(PVPS)(SOPD) showed irreversible two step reduction, such as Co(Ⅲ)/Co(Ⅱ) and Co(Ⅱ)/Co(Ⅰ), and Ni(Ⅱ)(PVPS)(SND), Ni(Ⅱ)(PVPS)(SOPD), Cu(Ⅱ)(PVPS)(SND), and Cu(Ⅱ)(PVPS)(SOPD) complexes showed irreversible one step reduction, such as Ni(Ⅱ)/Ni(Ⅰ) and Cu(Ⅱ)/Cu(Ⅰ), respectively.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.133-139
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• 2002

Core-shell polymers of inorganic/organic pair, which are consisted of both core and shell component, were synthesized by sequential emulsion polymerization using ethyl methacrylate (EMA) as a shell monomer and ammonium persulfate as initiator. We found that $CaCO_3$ core should be prepared by adding 2.0wt% SDBS(sodium dodecyl benzene sulfonate), $CaCO_3$ core/PEMA shell polymerization was carried out on the surface of $CaCO_3$ particle during EMA shell polymerization in the core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring the degree on decomposition of $CaCO_3$ by HCI solution, thermal decomposition of polymer composite on thermogravimetric analyzer, glass transition temperature on differential scanning calorimeter, and morphology using scanning electron microscope.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.116-116
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• 2009

$TiO_2$ pastes was synthesized to obtained of high efficiency dye-sensitized solar cells using size dependent co-polymer. SBM co-polymer binder is consist of styrene, n-butyl acrylate, and methacrylic acid (SBM) monodisperse co-polymer binder materials and this $TiO_2$ pastes were applied of dye-sensitized solar cells (DSSCs). The photoanodes were characterized by ATR-Fourier Transform spectrometer, X-ray diffraction (XRD) and morphology was investigated by field emission scanning electron microscopy (FE-SEM). The photoelectrochemical properties of the thin films and the performance of DSSCs were measured by photovoltaic-current density, AC impedance and monochromatic incident photon-to-current conversion efficiency (IPCE). DSSC based on the 100nm size co-polymer binder was obtained conversion efficiency of 8.1% under irradiation of AM 1.5(100 $mWcm^2$).

• Journal of Environmental Science International
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• v.13 no.3
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• pp.319-325
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• 2004

An experimental study on the preparation of monolithic porous polymers by environmentally friend process in supercritical carbon dioxide has been carried out. Polymerization mixture composed of a cross-linking monomer, initiator and functional co-polymer was charged in the reactor with sapphire window. After the system was purged with a flow of $CO_2$ for 15 min, the reactor was pressurized with liquid $CO_2$ up to 100 bars. The reactor was isolated from and placed back to the system via quick connector for shaking until the mixture had become fully homogeneous. The reactor was then heated and pressurized to the required reaction conditions and left overnight. After cooling and $CO_2$ evacuation, the polymer was removed from the reactor as dry, white, continuous monoliths. The effect of experimental conditions on the physical properties of porous polymer was systematically examined, and it was found that monomer content had a major effect on the physical properties of the polymers.