• Polymer(Korea)
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• v.27 no.3
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• pp.265-270
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• 2003

In spite of high ionic conductivity, the polymer gels have poor mechanical properties and high reactivity with lithium metal anode. To solve these problems, the dry solid systems and polymer composites have been intensively studied, due to their good mechanical, thermal, chemical, and electrochemical stability. The objectives of this experiment were to improve ionic conductivity and mechanical properties of the solid polymer electrolytes based on PEO-LiClO$_4$. To obtain higher ionic conductivity and better mechanical properties, ceramic or rubber phase was added in the PEO-LiClO$_4$(8:1) matrix. The results showed that ionic conductivity and mechanical properties were improved. The ionic conductivity of the samples was as high as 10$\^$-5/ S cm$\^$-1/. This value is similar to the best ionic conductivity ever reported in the solid drying system. To obtain better results, we used PEO with various molecular weights (600∼8000) and changed the salt contents. By using DSC, we found that the addition of salt reduced the crystallinity of PEO. The mobility of polymer dependence on salt contents was examined by FT-IR.

• Polymer(Korea)
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• v.36 no.1
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• pp.104-110
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• 2012

The dispersion of pigment particles is important because it is capable of increasing the color strength, contrast, and transmittance of color-LCD products. Pigment dispersion properties are very important factors for the quality of LCD color filters. The chemical structure of polymeric dispersants for pigment is important to improve dispersion stability and prevent aggregation or flocculation of pigment in organic or aqueous systems. Polymeric dispersants should contain both anchoring group that interacts with pigment surface and stabilizing group that provides steric stabilization. Moreover, the molecular weight and composition of block copolymer have the an effect on pigment dispersion. In this study, adequate dispersants, block copolymers containing (2-dimethylamino)ethyl methacrylate as anchoring group and oligo(ethylene oxide)methyl ether methacrylate as a stabilizing group were designed and synthesized by atom transfer radical polymerization in order to prepare well-defined structure, molecular weight and composition.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.261-266
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• 2005

Quaternary ammonium compounds(QACs) are some of the most commonly used antimicrobials. Antimicrobial polymers have been used as biomedical devices. In this Study, We synthesized new methacrylate monomers including quaternary ammonium moieties for preparation of contact lens, And also, we tested for antimicrobial activities against S. aureus, E. coli and P. aeruginosa. They showed much higher antimicrobial activities against all than the polymers of no including quaternary ammonium.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.35-35
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• 2003

목적： 나노 산화철 입자 및 생고분자인 PCL(Polycarprolacton)로 표면 코팅한 T2 MR 조영제를 합성하고 동물 종양 모델을 이용하여 In vivo 특성을 조사하고자 하였다. 대상 및 방법： $FeC1_2$.$4H_2$O와 $FeC1_3$.$6H_2$O을 무게비를 1：2로 정량하여 첨가하고 NaOH 혹은 TMAOH로 pH를 조절한후 PCL를 첨가하여 magnetite가 생성되는 동시에 고분자로서 코팅을 한후 증류수로 여러번 씻어준다. TEM, SEM, DLS 및 IR spectroscopy와 SQUID등을 측정하여 최종 반응물의 입자크기, 자성, 코팅 상태등을 평가하였다. 최소의 입자크기를 형성하는데 필요한 실험 조건을 찾기 위해 반응온도, 코팅할 고분자의 함량, 교반속도별로 실험하여서 최적의 조건을 찾으려 하였다. 토끼의 간에 VX2 암종을 이식한 동물 모델을 이용하여 PCL로 표면 코팅된 나노자성체의 in vivo 영상 특성을 알아보았다.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.111-114
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• 2001

폴리프로필렌 섬유는 강도, 인성, 내마모성, 레질리언스 등의 물리적 성질이 우수하여 각종 산업용 소재로 폭 넓게 사용되고 있다[1]. 그러나 폴리프로필렌은 장점도 많지만 분자구조 특성으로 인하여 대전방지성, 소수성 등과 같은 표면특성들이 좋지 안은 단점도 있다[2,3]. 따라서 폴리프로필렌의 표면특성을 개질 하기 위하여 금속화합물, 고분자 첨가제를 혼합시키는 방법[4,5], 물리적ㆍ화학적으로 섬유를 처리하는 방법, 공중합과 벨렌드에 의한 방법 등이 사용되어 왔으며, 최근에는 유기물 고분자에 비하여 내열성, 내절연성, 그리고 표면특성이 우수한 실리콘을 공중합하여 변성수지를 개발하거나 블렌드하는 방법등이 이용되고 있다. (중략)

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.257-263
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• 1998

Alcaligenes eutrophus was successfully recovered from high cell density broth by pre-treatment with Fe-based coagulants. An inorganic coagulant, Fe$_2$(SO$_4$)$_3$, and a polymerized coagulant, Ferix-3, were used. Good coagulation was observed in broad pH range of 3 to 13, the floe size was increased with increasing pH of culture broth. The optimum pH of fermentation broth for cell recovery was 10 to 13. The optimum coagulant dosages to recover cells with 95% cell recovery were increased with increasing cell concentration. Optimal coagulant dosage was lower when the polymerized coagulant was used rather than the inorganic coagulant. The coexistence of NH$_4$$\^$+/ was increased coagulant requirement, and the coagulant requirement was 0.066g Fe$_3$$\^$+//g NH$_4$$\^$+/.

• Elastomers and Composites
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• v.37 no.4
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• pp.224-233
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• 2002

This study has investigated the flame retardant properties of EPDM rubber with the addition of various flame retardants. Carbon black, stearic acid, zinc oxide cross-linking agent were mixed with EPDM rubber to produce the base rubber E0 without the addition of flame retardants. Phosphorus flame retardant Tricrecyl phosphate(TCP) was added to E0 in 0.5, 1, 1.5, 2 phr to make E1~E4 samples and red phosphorus was added in 3, 6, 9, 12 phr to make E5~E8 samples. A flame retardant of the bromine family Decabromodiphenyloxide(DBDPO), and a chlorinated paraffin retardant of the chlorine family was added to E0 in 3, 6, 9, 12 phr to make E9~E12 and E13~E16 samples, repectively. Basic physical properties such as tensile strength, tear strength and hardness were measured for all the rubber samples with various flame retardant additions. There was no substantial differences. On the other hand, Oxygen index and UL94 were measured to study flame retardant properties. From oxygen index measurements E0 sample showed a value of 23.5%, indicating the improvement of flame retardant properties. Also from UL94 measurements, it was found that addition of red phosphorus resulted in maximum flame retardant effect. It was found that increasing the amount of addition resulted in decreasing combustion rate and improving flame retardant effect regardless of the kind of flame retardant.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2003.11a
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• pp.356-356
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• 2003

• Polymer(Korea)
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• v.36 no.2
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• pp.182-189
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• 2012

In this study, poloxamer hydrogels were prepared by electron beam irradiation and evaluated for potential application as a buccal mucoadhesive drug delivery system. Poloxamer, one of typical thermoresponsive polymers, was modified to have vinyl end groups for crosslinking reaction, and its hydrogels were fabricated by irradiation crosslinking reaction. Carbopol as a mucoadhesive polymeric additive was introduced to improve the mucoadhesive property of the hydrogels and its effect on the mucoadhesion and drug release properties was investigated. The results showed that the end group modification of poloxamer and the addition of carbopol improved mucoadhesive force and mechanical properties and led to a sustained drug release behavior.

• Polymer(Korea)
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• v.25 no.4
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• pp.568-574
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• 2001

PEO-like solid polymer electrolytes based on bisphenol A ethoxylate acrylate were synthesized and their electrochemical properties and mechanical stability were studied. Low molecular weight poly(ethylene glycol) dimethyl ether (PEGDMe) was added to increase the conductivity of the electrolyte. The maximum conductivity of the resulting polymer electrolyte was found to be 1.0 ${\times}$ 10$^{-3}$ S/cm [Bisphenol A ethoxylate diacrylate ([EO]/[phenol]= 15), PEGDMe250 80 wt%, LiCF$_3SO_3$] at 30$^{\circ}$C. Tensile strength of the free standing polymer electrolyte films was measured to be in the range of 0.4 ~ 5 MPa and these polymer electrolyte films did not show a crack even in 90$^{\circ}$ and 180$^{\circ}$ bending against ${\phi}$=3 mm bar. These electrolytes showed oxidation stability up to 4.5 V vs. lithium reference electrode.