• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.87-89
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• 1997

1. 서론 : 막을 이용한 분리기술의 실용화의 최대 과제는 선택성이 높고 용매의 투과용매의 투과속도가 높은 막재질 및 처리 면적이 큰 막의 개발이 필요하게 되었다. 이러한 성능 개발은 1960년대 cellulose acetate 계통의 막개발 이후 1980년대 지지층 고분자위에 다른 고분자 물질을 도포한 복합막(thin film composite layer)이 개발되어 막의 성능을 급격히 발전시켰다. 그 중에서 초박막화(ultrathin membrane)는 분리막에 의한 분리공정의 최대 결점인 낮은 투과량의 개선을 꾀할 수 있다는 장점 때문에 다양한 시도가 이루어지고 있다. 이러한 박막 제조 방법에는 박층분산법, 침지코팅법, 기상증착법, 계면중합법이 있으나, 섞이지 않는 두 계면 사이에서 고분자를 형성시키는 계면중합법은 수용상에 함침된 지지막위에 유기상을 계변에서 중합시켜 박막을 얻는 기술이다. 중합과정에서 일어나는 계면의 형성과정에 대한 연구는 미흡하기에 이에 본 연구는 시간에 따른 계면중합 반응 형성과정을 고찰하는 방법을 소개하고, 형성된 박막의 아론적, 실험적 두께 측정을 비교하였다.

• Journal of the Korean Chemical Society
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• v.23 no.6
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• pp.402-411
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• 1979

The synthesis of pyrrolidone-N-sulfonyl chloride has been carried out by the reaction of pyrrolidone with sulfuryl chloride in benzene. It was attempted to study the catalytic effect of pyrroldone-N-sulfonyl chloride as an initiator for anionic polymerization of pyrrolidone. It was found that as a concentration of initiator decreased, inherent viscosity of the resulting polymer increased up to 1.8 dl/g. The highest rate of polymerization and equilibrium conversion was observed when mole ratio of PNSC to KOH was 0.25. In general, the observed value of polymerization and equilibrium conversion in circumstances using PNSC/KOH catalysis system were higher than using $CO_2$/KOH catalysis system.

• Polymer(Korea)
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• v.37 no.1
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• pp.80-85
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• 2013

Anionic polymerization of hexafluoropropylene oxide (HFPO) was investigated under various reaction conditions such as various hexafluoropropylene (HFP) oligomers composed of dimer and trimer, reaction temperatures, and feeding rates of hexafluoropropylene oxide monomer. HFP oligomer was synthesized from cesium fluoride (CsF) and HFP in tetraethyleneglycol dimethylether (TG). Under 5 g of CsF, 200 g of HFP, 10 g of TG, and reaction temperature $30^{\circ}C$, HFP dimer content in oligomer was relatively increased. HFPO oligomer with a high molecular weight ($M_w$ 3600) was synthesized in conditions of reaction temperature $0^{\circ}C$, HFP oligomer with 35.1% of dimer, and 1.85 g/min of HFPO feeding rate. Otherwise, chain transfer was increased under unoptimized reaction conditions. Consequently, it was found that reaction conditions impact chain propagation and chain transfer in the anionic polymerization of HFPO.

• Membrane Journal
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• v.27 no.6
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• pp.506-510
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• 2017

The interfacial polymerization method has been applied to various fields as a reaction in which reactive monomers dissolved in two immiscible solutions cause polymerization at the interface. In the case of water treatment membranes, m-phenylene diamine and trimesoyl chloride are used as reactants. The performance of the membrane is affected by various polymerization factors. In this study, we investigated how the spreading rate of the organic solution influences the surface and structure of the membrane. Spreading rate of organic solutions was adjusted to 7.6 and 25 mm/sec. The solution volume of the organic phase was adjusted to 1~3 drops. The observed results showed that cracks were not found in the polyamide membrane when dropping at a drop of 7.6 mm/sec and dropping two drops at 25 mm/sec. On the other hand, cracks occurred in all cases. Therefore, the spreading rate of the initial organic solvent is expected to greatly affect the performance of the polyamide membrane.

• Proceedings of the Korean Fiber Society Conference
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• 1993.06a
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• pp.61-61
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• 1993

• Proceedings of the Korean Fiber Society Conference
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• 1991.06b
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• pp.32-32
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• 1991

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1027-1034
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• 2010

Effects of inorganic nano-powders on the polymerization and thermal degradation kinetics as well as the mechanical properties of polyurethane nano-composites were studied by both the measurement of polymerization temperature as a function of time and non-isothermal thermogravimetric analysis (TGA) as well as the Instron test. As the results from polymerization studies, the reaction rates of MMT-filled PU composites were faster than those of Ce500-filled ones, and moreover, the activation energies using Kissinger method for the thermal degradation of composites were calculated as 139.34 kJ/mol for the Ce500-filled PU composites and 91.12 kJ/mol for MMT-filled one, respectivel, exhibiting that MMT nano-powder seemed to be acting as the catalyst for both polymerization and degradation of PU composites. UTM result, however, showed that tensile strength at break of MMT-filled composites was much higher than that of Ce500-filled ones above the concentrations range of 5 phr in the composites.

• Nuclear Engineering and Technology
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• v.9 no.2
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• pp.65-74
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• 1977

The radiation-induced graft polymerization of acrylic acid onto polyester fabric was investigated with accelerated electron beams as ratiation source at high dose rates. Homopolymerization was suppressed by addition of cations which is known as homopolymerization inhibitor, but this practical advantage was obtained at the expense of grafting efficiency. The rate of grafting (%/sec) was proportional to the 0.82th power of dose rates over the range from 1.6$\times$10$^{6}$ to 10$\times$10$^{6}$ rad/sec. The grafted polyester fabric showed considerable improvement in moisture regain and antistatic properties.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.203-206
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• 2001

산업용 섬유로서 그 사용 범위가 다양해질 것으로 예상되는 고강도, 고탄성률 폴리비닐알코올(PVA) 섬유를 얻기 위해서는 먼저 분지 구조가 없는 고분자량의 PVA의 합성이 필요하다. 그러나 비닐아세테이트와 같은 비공역형 단량체는 성장종 라디칼종의 활성이 매우 커서 성장반응 속도와 정지반응 속도가 매우 빠르므로 연쇄 이동반응이 빈번하게 일어나 고분자량의 중합체를 얻기 힘들고 또 분지구조를 갖게된다. (중략)

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.148-153
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• 2003

고분자 물질은 유기용제를 사용하여 제조되는 경우가 일반적이다. 이들 중에서 용제형 아크릴계 고분자는 점착강도, 내습성, 내수성 그리고 내열성 등이 우수하여 페인트, 접ㆍ점착제, 섬유 등의 산업전반에 이용되고 있으나 용제사용에 따른 화재의 위험성과 환경적인 문제점 때문에 규제의 대상이 되고 있다. 이러한 위험성과 환경문제점은 유화중합법에 의해 고분자물질을 제조함으로써 해결되며, 그 중에서 단계 유화중합법은 다른 중합법에 비해 온도조절이 용이하며, 반응속도와 분자량을 조절할 수 있다는 장점 때문에 latex 공업이나 고분자 blending 기술면에서 많이 이용되고 있는 실정이다.(중략)