• 대한화학회지
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• 제29권2호
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• pp.164-171
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• 1985

SAF 축합중합체와 CHBM-DVB 공중합체를 합성하였다. 이들 합성된 이온교환체의 이온교환용량은 각각, 4.6meq/g and 3.9 meq/g이었다. 또한 이들 약산성 이온교환체에 대한 몇가지 금속이온들의 흡착능과 이온교환체 성질에 대하여 논의하였다. 그리고 이온들의 염산용액중에서의 분포계수와 몇가지 용리현상에 대하여 논의하였다.

• 한국염색가공학회지
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• 제15권4호
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• pp.57-64
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• 2003

Poly(ethylene-co-vinyl acetate)(EVA) microspheres were prepared by a thermally induced phase separation. The microsphere formation occurred by the nucleation and growth mechanism in the metastable region. The diluent used was toluene. The microsphere formation and growth was followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by SEM observation and particle size analyzer, became broader when the polymer concentration was higher, the content of vinyl acetate in EVA copolymer was higher, and the cooling rate of EVA copolymer solution was lower.

• 한국염색가공학회지
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• 제17권4호
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• pp.15-20
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• 2005

Poly(ethylene-co-vinylacetate)(EVA) microspheres were prepared by thermally induced phase separation in toluene. The microsphere formation occurred by the nucleation and growth mechanism in metastable region. The effects of the polymer or pigment weight percentage and cooling rate on microsphere formation were investigated. The microsphere formation and growth were followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by particle size analyzer, became broader when the polymer concentration was higher, the pigment concentration and the cooling rate of EVA copolymer solution were lower.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.329-329
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• 2006

Various new active ester monomers based on (meth)acrylates and 4-vinylbenzoic acid have been prepared. Investigation of the controlled radical polymerization behavior of the respective monomers resulted in excellent polymerization control, thus, opening synthetic routes to reactive block copolymers. Polymer analogous reactions with amines yielded functional polymers. In the case of the copolymer poly(N-isopropylacrylamide-co-acetone oxime acrylate) a lower critical solution temperature could be measured at $52^{\circ}C$. Thus, the reactive copolymer features two characters: reactive AND stimuliresponsive behavior.

• Macromolecular Research
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• 제9권5호
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• pp.259-266
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• 2001

Multiblock copolymer was synthesized by the copolycondensation of oligo(L-lactic acid) prepared by thermal dehydration of L-lactic acid, Pluronic$\^$TM/(PN) and dodecanedioic acid as carboxyl/hydroxyl adjusting agent. This polycondensation proceeded by catalysis of stannous oxide to give the multiblock copolymers with high molecular weight and wide range of compositions. Polymer film was prepared by casting the chloroform solution of the multiblock copolymers having different composition. The multiblock copolymers having relatively high contents of poly(L-lactide) were melt spun into filaments which were subsequently drawn at 60$^{\circ}C$. The copolymer films and the filaments showed an improved flexibility due to the incorporation of the soft segments.

• Bulletin of the Korean Chemical Society
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• 제25권3호
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• pp.351-356
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• 2004

Selected MPEG-b-PDLLA block copolymers have been synthesized by ring-opening polymerization with systematic variation of the chain lengths of the resident hydrophilic and hydrophobic blocks. The size and shape of the micelles that spontaneously form in solution are then controlled by the characteristics of the block copolymer template. All the materials prepared in this study showed the tunable pore size of 20-80 ${\AA}$ with the increase of hydrophobic chain lengths and up to 660 $m^2$/g of specific surface area. The formation mechanism of these nanoporous structures obtained by controlling the micelle size has been confirmed using both liquid and solid state $^{13}C\;and\;^{29}Si$ NMR techniques. This work verifies the formation mechanism of nanoporous structures in which the pore size and wall thickness are closely dependent on the size of hydrophobic cores and hydrophilic shells of the block copolymer templates.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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• pp.49-49
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• 2002

A strategy for the synthesis of more stable and large periodic mesoporous organo-silica materials has been developed for the 2D hexagonal mesoporous organosilica by the core-shell approach using nonionic PEO-PLGA-PEO triblock copolymer templates. The BET surface area of the solvent-extracted hexagonal mesoporous organosilica is estimated to be 1,016 ㎡/g and the pore volume, pore diameter, and wall thickness are 1.447 ㎤/g, 65 Å, and 43 Å, respectively. More hydrophobic PLGA block than the PPO block used for templates of mesoporous silica proves to be quite effective in confining the organosilicates within the PEO phase. Reaction temperature and acid concentration of an initial solution as well as the chemical nature of the bloc k copolymer templates also demonstrate to be important experimental parameters for ordered organosilica mesophase. Moreover, the mesoporous organosilicas prepared with the PEO-PLGA-PEO block templates maintain their structural integrity for up to 25 days in boiling water at 100℃. The mesoporous materials with large pores and high hydrothermal stability prepared in this study has a potential for many applications.

• 대한화학회지
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• 제14권4호
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• pp.333-339
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• 1970

1) The copolymerzation of acrylamide $(M_1)$ with styrene $(M_1)$ was studied in absolute methanol solution at $50^{\circ}C$, using azobisisobutyronitrile as a initiator. The monomer reactivity ratios determined at $50^{\circ}C$ were as follows: $r_1=0.2,\;r_2=1.05$ and from these values, Q and e values for acrylamide were calculated as 0.37$(Q_1)$ and 0.45 $(e_1)$. 2) Overall activation energy of copolymer was calculated to 24.3K/cal mol, using the Arrhenius epuation. 3) Measurement of intrinsic viscosity and observation of physical properties were made on the copolymer.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.66-69
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• 1998

1. 서론 : 본 연구는 시간이 경과함에 따라 free volume감소로 나타나는 PTMSP[Poly(1-trimethylsilyl-1-propyne)] memebrane의 pysical aging을 늦추거나 방지할 목적으로 PTMSP polymer를 합성하여 여기에 hydroxy-terminated PDMS를 graft시켜 PTMSP/PDMS graft copolymer를 제조하였다. 용매증발법에 의해 PTMSP memebrane 및 PTMSP/PDMS graft copolymer memebrane을 제막한 후 PTMSP막의 물리적 노화를 관찰하기 위한 시점에서 조업시간에 따른 이들 막의 transport property을 살펴 보았다. 또한 이들 polymer을 사용하여 0.5 wt%의 희박 dope solution을 제조한 후 여기에 상전환법에 의해 제조된 비대칭 PEI(polyetherimide)지지막을 dip-doping시켜 PTMSP-PEI, PTMSP/PDMS-PEI 복합막을 제조하여 상기의 두 막과 투과증발 특성을 상호 비교하여 보았다. 그리고 객관적 비교 자료를 얻을 목적으로 PDMS막과 PDMS-PEI 복합막을 각각 제막하여 동일조건에서 실험을 수행하였다. 따라서 본 연구는 수중에 미량 용해된 chloroform, trichloroethylene, perchlororthylene, 1,1,1-trichloroethane 등의 유기염소계화합물 제거 실험을 통해 PTMSP, PTMSP/PDMS 등의 dense membrane과 asymmetric composite membrane 사이의 상관관계 및 이들 막들의 투과특성을 서로 비교, 분석하는데 목적을 두었다.

• Bulletin of the Korean Chemical Society
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• 제6권3호
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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.