• Macromolecular Research
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• 제16권8호
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• pp.676-681
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• 2008

The $\pi$-complex membranes of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) of two silver salts of $AgBF_4$ and $AgCF_3SO_3$ were prepared and tested for the separation of the propylene/propane mixtures. The Fourier-transform infrared (FT-IR) spectra of these complexes showed that the silver salts were dissolved in SEBS up to a silver mole fraction of 0.14, due to $\pi$-complexation between the aromatic C=C bonds of styrene blocks and silver ions. Above this solubility limit, ion pairs and high-order ionic aggregates began to form, so that silver salts were distributed unselectively in both the EB and PS blocks. The domain size of the PS blocks was enlarged up to this critical concentration with increasing silver concentration without structural transitions, as confirmed by small angle x-ray scattering (SAXS). These structural properties of the SEBS/silver salt complexes may explain the lower separation properties for propylene/propane mixtures compared to poly(styrene-b-butadiene-b-styrene)(SBS)/silver salt complex membranes.

• Elastomers and Composites
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• 제50권3호
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• pp.189-195
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• 2015

In this study, we prepared epoxidized poly ethylene-ter-1-decene-ter-divinylbenzene (Epo-PEHV) as a reactive compatibilizer to prevent phase separation phenomenon which occurs upon blending polypropylene (PP) and ethylene-vinyl alcohol copolymer (EVOH). Firstly, PEHV was prepared under high catalyst activity according to content of catalyst and cocatalyst. After then, we modified vinyl group of the terpolymer with epoxy group. We observed that the terpolymer was successfully epoxidized by 1H-NMR and FT-IR analysis. The Epo-PEHV was added by 2, 5, 10% in PP/EVOH blends. The morphologies and mechanical properties of PP/Epo-PEHV/EVOH blends were analyzed by SEM and UTM, respectively. Epo-PEHV enhanced the interfacial adhesion of PP and EVOH blends.

• Elastomers and Composites
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• 제54권1호
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• pp.7-13
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• 2019

Recycling of waste polyvinyl chloride plastics has attracted much attention due to environmental problems, but the poor mechanical properties, low thermal stability, frequent breakage of strands, and melt cracking of the waste plastics have limited their widespread use. To overcome these disadvantages of waste PVC (W-PVC), recycled PVC powder blend was prepared by adding high-density polyethylene (HDPE) and ethylene vinyl acetate (EVA) as a heat stabilizer and compatibilizer, respectively. An intermeshing co-rotating twin screw extruder was used to prepare the blend, and the characteristics of the blend were analyzed by SEM and TGA, and by using a UTM and Izod impact tester. The impact strength was improved as the EVA content increased for the W-PVC/HDPE (80/20 wt%) blend. As the HDPE and EVA contents increased in the W-PVC/HDPE/EVA blend, the impact strength increased. SEM observations also revealed the improved interfacial adhesion for the EVA-containing blend.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3653-3659
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• 2015

방향족 열방성 액정 고분자와 에틸렌-아크릴 산 공중합체 및 그 금속염 고분자간의 반응 상용화에 관하여 연구하였다. 블렌드는 배치 믹서에서 제조하였으며 액정 고분자의 에스터 그룹과 이오노머의 아크릴산 사이에 발생하는 acidolysis 반응으로 형성되는 그라프트 공중합체의 발생 유무를 평가하였다. 반응의 정도는 배치 믹서에서 시간에 따른 토크의 증가와 열분석 및 형태학 상 구조를 통해 평가하였다. poly(ethylene-co-acrylic acid) (EAA) 이오노머의 Na 염이 반응을 증진시키는데 특히 효과적임을 알 수 있었다. 반응의 진행 정도는 금속염의 종류 뿐 아니라 이오노머의 조성과 반응 시간에 따라 변하였다. 액정 고분자와 Na로 중화된 이오노머 간의 반응으로 생성된 그라프트 공중합체는 액정 고분자와 EAA 이오노머 블렌드의 반응상용화제로 효과가 높음을 미세 구조 분석을 통하여 알 수 있었다.

• Advances in materials Research
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• 제6권3호
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• pp.303-316
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• 2017

In this article, novel olefin polymerization catalyst with lower cost and simple synthetic process were developed, $ArOTiCl_3$ complexes [$(2-OMeC_6H_4O)TiCl_3(C1)$, $(2,4-Me_2C_6H_3O)TiCl_3(C2)$, $TiCl_3(1,4-OC_6H_4O)TiCl_3(C3)$, $TiCl_3(1,4-OC_6H_2O-Me_2-2,5)$ $TiCl_3(C4)$] and corresponding $(ArO)_2TiCl_2$ complexes [$TiCl_2(OC_6H_4-OMe-2)_2(C5)$ and $TiCl_2(OC_6H_3-Me_2-2,6)_2(C6)$] have been synthesized by the reaction of $TiCl_4$ with phenol, all these complexes were well characterized with $^1H$ NMR, $^{13}C$ NMR, MASS and EA. When combined with methylaluminoxane (MAO), the $ArOTiCl_3/MAO$ system shows high activity for ethylene copolymerization with 1-octene and copolymer was obtained with broaden molecular weight distribution (MWD). The $^{13}C$ NMR result of polymer indicates that the 1-octene incorporation in polymer reached up to 8.29 mol%. The effects of polymerization temperature, concentration of polymerization monomer and polymerization time on the catalytic activity have been investigated.

• 폴리머
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• 제30권5호
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• pp.432-436
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• 2006

인덴과 메틸인덴 리간드를 가지고 폴리메틸렌 다리결합으로 구성된 두 금속 CGC (constrained geometry complexes) 촉매를 합성하여 에틸렌과 스티렌 공중합을 행하였다. 촉매 구조에 따른 공중합 활성과 공중합체의 구조 및 열적 성질을 조사하였다. 12-메틸렌 및 9-메틸렌 다리결합을 가진 촉매의 환성은 상업용 CGC 촉매와 6-메틸렌 다리결합을 가진 촉매의 활성보다 4배 이상 높게 나타났는데, 이는 6-메틸렌 다리결합은 입체적으로 중심금속간은 인접한 거리에 위치하게 되어 입체장애에 의해 촉매활성이 감소하게 된다. 다리결합의 길이가 긴 두 금속촉매를 사용하여 제조한 공중합체의 스티렌 함량이 6-45 mol%로 나타났으며, 단량체 공급비([Styrene]/[Ethylene])가 5.0 이상에서는 다리결합의 길이가 긴 촉매로 얻은 공중합체의 $T_m$이 관찰되지 않는 비결정의 공중합체가 생성되었으며, 스티렌의 함량이 증가할수록 공중합체의 $T_m$은 급격히 감소하여 스티렌 함량이 약 11mol% 이상에서는 결정성이 없는 랜덤 공중합체가 생성되었다. C-NMR로 공중합체의 미세구조를 분석한 결과 스티렌 블록이 존재하지 않는 랜덤 공중합체임을 확인할 수 있었다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2002년도 봄 학술발표회 논문집
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• pp.352-354
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• 2002

A series of ABA type triblock copolymers of trimethylene carbonate (TMC) and $\varepsilon$-caprolactone($\varepsilon$-CL) with different molar ratio were synthesized using ethylene glycol as initiator and stannous octoate as catalyst by ring-opening bulk polymerization. The characterization of the triblock copolymers was characterized by $^1$H-NMR, $\^$13/C-NMR, FT-IR, GPC and DSC, and compared with random copolymer. (omitted)

• 한국염색가공학회지
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• 제13권6호
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• pp.405-412
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• 2001

In order to impart dyeability on to Polypropylene fiber, PP/EVA blend in the form of fibers and film were preparared using melt blending process. Ethylene vinylacetate containing 28wt% of vinylacetate(EVA(28)) was used as a copolymer. In the study of mechanical properties, tenacity and initial modulus decreased with Increasing EVA concentrations, whilst extension at break increased with increasing EVA contents. Their results in the dyeing behavior show that dye adsorption increased with increased EVA contents iota both blend fibers and films. The extent of dye uptake of red dye to modified polypropylene fibers was greater than that of Blue and Yellow counterparts due to the difference behavior of dye particles in dyeing bath.

• 한국염색가공학회지
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• 제13권6호
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• pp.47-47
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• 2001

In order to impart dyeablility on to Polypropylene fiber, PP/EVA blend in the form of fibers and film were preparared using melt blending process. Ethylene vinylacetate containing 28wt% of vinylacetate(EVA(28)) was used as a copolymer. In the study of mechanical properties, tenacity and initial modulus decreased with increasing EVA concentrations, whilst extension at break increased with increasing EVA contents. Their results in the dyeing behavior show that dye adsorption increased with increased EVA contents for both blend fibers and films. The extent of dye uptake of red dye to modified polypropylene fibers was greater than that of Blue and Yellow counterparts due to the difference behavior of dye particles in dyeing bath.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.196-196
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• 1994

DDS에 활용될 수 있는 고분자 소재를 개발할 목적으로 물성 및 응용성이 우수한 고분자 겔에 관한 연구를 수행하였다. Ethylene oxide,propylene oxide 각각의 copolymer인 poloxamer등의 prepolymer들을 triisocyanate로 가교시키고 diisocyanate 로 chain이 연장된 "soft hydrogel"을 제조하였다. 모델 약물을 선정하여 crosslinker와 extender의 조절에 따른 hydrogel의 약물 방출 조절능을 조사하였으며 그 기전을 규명하고자 하였다. 가교부위에 urethane bond를 함유한 soft hydtogel은 건조상태에서도 고무와 같은 전연성을 보여 일반적인 hydrogel과 대비되는 특성을 보였으며 이에 따른 다양한 활용성이 기대되었다. Extender및 crosslinker의 비율에 따라서 이 rubber elasticity가 조절되었다. 가교도가 감소할수록 팽윤도가 상승하였고 이에 따른 약물방출도 증가함을 확인하였다. 또한 Prepolymer의 분자량 및 친수/소수성등의 물성에 따라 약물방출을 조절할 수 있었다. 제조된 hydrogel에 조절방출시 필요한 기능을 부가시키고자 poly(carylic acid)류와 IPN 공중합체를 합성하여 물성을 조사하였고 비이온성/양이온성/음이온성 모델약물을 선정하여 pH에 따른 가변적 팽윤도와 이온성 상호작용등에 근거한 약물 조절방출기전을 조사하였다.기전을 조사하였다.