• Bulletin of the Korean Chemical Society
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• 제7권3호
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• pp.238-240
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• 1986

Complex formations between syndiotactic poly(methacrylic acid) (st-PMAA) and poly(N-vinyl pyrrolidone) (PVP), and that between st-PMAA and polyethyleneoxide (PEO) through hydrogen bonding were studied by viscometry and potentiometry. Reduced viscosity (${\eta}_{red}$) was measured at various mole fraction of PVP or PEO with respect to a constant amount of st-PMAA. Observation shows a sharp minimum at the 1:1 mole ratio of st-PMAA:PVP or st-PMAA:PEO, which shows that the complexation becomes optimal and the complex has a compact structure in this ratio. Variation of pH also supports this conclusion. This is the case of the system of st-PMAA and PVP in water as well as in DMF. Also the complexation is much enhanced when the molecular weight of PVP is high. Meanwhile, the system of st-PMAA and PEO shows a little different behavior, i.e., this system does not form the complex in DMF and does only in water. It is because the interaction st-PMAA with PEO is weaker than that with PVP.

• 멤브레인
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• 제15권3호
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• pp.206-212
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• 2005

본 연구는 에스텔화 막반응공정에 의한 2,2,2-trifluoroethyl metacrylate (TFEMA)의 생산을 위한 선행연구로, 가교된 poly(vinyl alcohol)막을 이용하여 TFEA (2,2,2-trifluoroethanol)/water과 MA (methacrylic acid)/water 혼합용액을 대상으로 투과증발특성을 연구하였다. 산 저항성을 가진 가교된 PVA막은 PVA와 EGDE를 같이 녹인 수용액을 Teflon plate 위에 캐스팅한 후 $140^{\circ}C$에서 열 가교시킴으로써 제조하였다. 제조된 막의 특성을 알아보기 위해 FT-IR과 팽윤도 측정을 실시하였다. TFEA/water 혼합용액에 대한 투과증발실험은 가교제인 EGDE농도와 운전온도를 변화시켜가면서 실시하였으며, MA/water 혼합용액에 대한 투과증발실험은 최적화된 PVA막을 가지고 실시하였다. 투과증발실험결과로부터 제조된 막은 TFEA와 MA의 에스테르화 반응온도인 $80^{\circ}C$ 이상에서 $96\%$의 TFEA 및 MA 수용액에 대해 각각 100, 900 이상의 매우 높은 물에 대한 선택도와 0.1, $0.3\;kg/m^2h$의 투과도를 얻을 수 있었다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.157-162
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• 1996

Poly(vinyl alcohol)(PVA)-poly(methacrylic acid)(PMAA) 계의 방사능 고정화에 대한 일련의 실험을 수행하였다. 전위차 적정 데이터와 FT-IR spectra 를 해석하여 PVA-PMAA 계의 화학적 특성을 설명하였다. 인위적으로 오염시킨 모래에 대한 침출실험 결과, $^{241}$Am, $^{154,155}$ Eu, $^{144}$ Ce의 전이 계수가 $^{l34,137}$ Cs 에 비해 높은 것으로 나타났다. 실험에 사용된 고분자 용액중, PVA-PMAA 계는 전체 방사능의 85% 이상을 차지하는 Cs 의 고정화에 효과적이었다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4239-4243
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• 2011

Biocompatible hydrogels from 2-hydroxyethyl methacrylate (HEMA) monomer containing various amount of alginate in the presence and absence of hydrophilic methacrylic acid (MAA) were synthesized in order for biomedical application. The antimicrobial effect and interaction with proteins for hydrogels were investigated in this study. MAA was introduced because it was expected to increase the amount of water content in the polymer which is an important factor for biocompatibility, and alginate was expected to enhance the antimicrobial activity. The antimicrobial effect against S. aureus and E. coli increased for all hydrogels as the amount of alginate and MAA contained. Presence of MAA further enhances the antimicrobial effect. Amount of adsorption of bovine serum albumin (BSA) increased with increasing concentration of alginate whether MAA was present or not. Contrarily, the amount of lysozyme was not affected with increasing alginate concentration in the absence of MAA, while it decreased in the presence of MAA.

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.71-76
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• 2006

Porous polymer monolithic columns were prepared by the direct free radical copolymerization of methacrylic acid and ethylene glycol dimethacrylate within the confines of a chromatographic column in the presence of toluene-dodecanol as a porogenic solvent. The separation characteristics of the monolithic columns were tested by a homologous series of xanthine derivatives, theophylline and caffeine. The effects of the polymerization mixture composition and polymerization condition, mobile phase composition, flow rate and temperature on the retention times and separation efficiencies were investigated. The results showed that the selection of correct porogenic solvents and appropriate polymerization conditions are crucial for the preparation of the monolithic stationary phases. The separation efficiency was only extremely weakly dependent on flow rate and temperatures. Hydrogen-bonding interaction played an important role in the retention and separation. Compared with conventional particle columns, the monolithic column exhibited good stability, ease of regeneration, high separation efficiency and fast analysis.

• 한국재료학회지
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• 제28권2호
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• pp.82-88
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• 2018

Stable slurries of YSZ in aqueous suspension with added polymer dispersants, namely, poly-methacrylic acid ammonium salt (PMMA), poly-acrylic acid (PAA) and poly-acrylic-co-maleic acid (PAMA), were mixed with the monomolecular dispersants citric acid and oxalic acid. The dispersion properties of the suspension were investigated using PSA, viscosity, sedimentation, and FT-IR. The polymer dispersants and monomolecular dispersants were attached to the YSZ surface by the carboxylic group, as shown by the FTIR results. A stabilized aqueous suspension was obtained when the polymer dispersant and citric acid were mixed and compared to the use of citric acid alone as a dispersant agent. When the polymer dispersant and citric acid were mixed and milled through attrition milling, there was a smaller particle size compared to when the polymer dispersant alone was used as a dispersant agent. This study determined that the particle size of the mixed dispersant was affected by the properties of the monomolecular dispersant and that the stability of the suspension was affected by the polymer dispersant. However, when slurries of YSZ were mixed with oxalic acid, the particle bridging behavior was the result of the high degree of viscosity and the small sedimentation height.

• 폴리머
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• 제25권5호
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• pp.671-678
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• 2001

Sodium 또는 zinc로 중화된 poly(ethylene-co-methacrylic acid)의 아이오노머는 ethylene 사슬 부분들로만 이루어진 결정상, acid 그룹이 존재하는 amorphous 영역, 그리고 ionic aggregate의 세 가지 상으로 나누어진다. Soaking에 의하여 흡수된 nonionic dye 분자들은 결정상을 제외한 amorphous 부분이나 ionic aggregate 분근에 존재하는데, 주위 사슬의 극성에 따라 dispersion force (ethylene 사슬 부분), polar force (acid 부분), ionic dipole (ionic aggregate 부분)의 세 가지 다른 힘의 영향 아래 놓이게 된다. 극성이 적은 ethylene 사슬부분의 dispersion force 영향 아래에 존재하는 Nile Red의 UV/Vis 흡수피크는 500nm 부근에서, polar한 acid 그룹의 영향을 받는 dye 피크는 525 nm, 그리고 ionic aggregate의 영향에 의한 dye는 Na+-아이오노머의 경우 550 nm, divalent이어서 더 큰 ionic dipole을 가지는 $Zn^{2+}$-아이오노머의 경우 610nm에서 각각 피크가 나타났다.

• Journal of Pharmaceutical Investigation
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• 제21권3호
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• pp.149-153
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• 1991

Polyethylene oxide (PEO)-polymethacrylic acid (PMAA) interpenetrating polymer networks (IPN) were synthesized via radical polymerization of PMAA and simultaneous crosslinking of PEO using triisocyanate. The equilibrium swelling of PEO-PMAA IPN was determined at different pHs. The swelling of PEO-PMAA IPN, ranged from 20% to 90%, was more sensitive than that of homo polymer PMAA gel This is probably due to protonation and deprotonation of the PMAA network and interpolymer complex formation between PEO and PMAA. Several model drugs were loaded into the IPN matrices and the release mechanisms were investigated. The release of nonionizable drugs such as ftorafur and prednisolone was controlled by swelling of the matrices. However, he release of propranolol, positively charged drug, was more affected by the ionic interaction between the drug and PMAA newtork, and the interpolymer complexation.

• 멤브레인
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• 제23권4호
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• pp.290-296
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• 2013

촉매 1,8-diazabicyclo[5,4,0]undec-7-ene(DBU)를 이용하여, poly(vinylidenefluoride-co-chlorotrifluoroethylene) P(VDF-co-CTFE) 고분자와 methacrylic acid (MAA)를 반응시켜, P(VDF-co-CTFE)-MAA 공중합체를 제조하였다. 또한 P(VDF-co-CTFE)-MAA와 2-sulfoethyl methacrylate (SEMA) 단량체를 4',4'-azobis(4-cyanovaleric acid) (ACVA) 개시제 하에서 자유 라디칼 중합하여 수소 이온 전도성 막을 제조하였다. SEMA 함량이 많아짐에 따라 술폰산 그룹이 증가하였다. SEMA 함량이 50%일 때 최대 이온교환 용량값이 0.82 meq/g에 도달하였으며 이는 함수량 결과와 일치하였다. 또한, SEMA 함량이 50%일 때 수소이온 전도도가 0.041 S/cm까지 도달하였다. 이러한 결과는 분리막에서 SEMA 함량이 증가할수록 수소 이온을 전달시킬 수 있는 이온그룹이 증가하기 때문이다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.94-94
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• 2003

Cross-linked polystyrene (PS) particles with carboxyl and/or poly(ethylene glycol) units on surface were formed by an emulsifier-free emulsion polymerization using styrene, methacrylic acid (MA), and poly(ethylene glycol) dimethacrylate (PEG-diMMA) at pH 7, and followed by freeze-drying to give the corresponding powders. Monodisperse polymer particles could be obtained at a concentration of PEG-diMMA 1 mol% relative to styrene. Zeta potential of polymer surface was measured to be 91 mV at a polymer of PEG-diMMA 1 mol% and was dropped as the content of MA increased.