• Macromolecular Research
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• 제17권8호
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• pp.603-608
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• 2009

Novel ultra-high molecular weight polyethylene (UHMWPE)/zirconia composites were previously prepared by the in situ polymerization of ethylene using a Ti-based Ziegler-Natta catalyst supported on to the surface of zirconia, as a bearing material for artificial joints. Tribological tests revealed that a uniform dispersion of zirconia in UHMWPE markedly increased the wear resistance. The effects of zirconia content on the oxidation behavior of the ${\gamma}$-ray-treated UHMWPE/zirconia composite surfaces were examined. The oxidation index that estimates the oxidation degree as the content of total carbonyl compounds was monitored using Fourier transform infrared spectroscopy-attenuated total reflectance. The changes in the surface composition due to the oxidation were confirmed by electron spectroscopy for chemical analysis. The extent of oxidation decreased with increasing zirconia content, which was attributed to the increased crystallinity as well as the decreased polymer portion of the UHMWPE/zirconia composites.

• 한국응용과학기술학회지
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• 제25권4호
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• pp.485-494
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• 2008

The acrylic coating emulsions were prepared by the emulsion polymerization to protect the surface of steel plate from the corrosion chemicals like acid, base and salt water. MMA(methyl methacrylate), styrene, BA(butyl acrylate), and 2-HEMA(2-hydroxyethyl methacrylate) were used as monomer. KPS(potassium persulfate) and SBS(sodium bisulfite) as redox initiator and SDBS(sodium dodecylbenzene sulfonate) as emulsifier were used on the emulsion polymerization reaction. The most stable in-situ coating was obtained when 10% of MMA was added. Both particle size and quantity in emulsion were decreased as increasing the mount of SDBS. the most stable prepared coating emulsion with polyisocyanate crosslinker showed very high anticorrosion properties on the coated steel layer to salt water, whereas no significant improvement of anticorrosion property to acdic and basic condition it showed.

• 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.

• 공업화학
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• 제27권1호
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• pp.80-85
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• 2016

넓은 비표면적과 큰 기공 부피를 갖는 실리카에 다양한 아미노실란 화합물을 in-situ 중합법을 통해 기능화 후 이산화탄소 흡착 특성을 확인하였다. 이산화탄소 흡착 기능기로 아민기가 포함된 아미노실란 화합물이 사용되었다. 흡착제의 흡착 특성 분석을 위해 질소 흡 탈착 실험과 원소분석, in situ FT-IR, TGA를 이용하였다. 흡착제 합성 전후를 비교하였을 때 폴리아미노실란이 기능화되면 표면적과 기공부피 및 크기가 감소하였으며 실리카 기공 부피의 70%에 해당하는 폴리아미노실란 화합물을 기능화 시켰을 경우 기공 부피의 100% 기능화 보다 이산화탄소 흡착능이 향상되었다. 흡착 온도를 비교하며 $30^{\circ}C$보다 $75^{\circ}C$에서 폴리아미노실란 화합물의 열팽창과 자유부피 증가로 흡착능이 증가하였고, 2NS/NPS-2의 경우 기공 부피 70% 기능화와 흡착 온도 $75^{\circ}C$에서 9.2 wt%의 높은 $CO_2$ 흡착능을 보였다.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2002년도 추계학술발표회 논문집
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• pp.155-158
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• 2002

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1992년도 제2차 학술발표초록집
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• pp.109-110
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• 1992

• 폴리머
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• 제28권2호
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• pp.177-184
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• 2004

고분자-점토 나노복합재는 적은 양의 점토 함유만으로도 물리적, 기계적 특성 등의 물성 증대 효과를 기대할 수 있다 고분자-점토 나노복합재의 일반적인 제조방법으로는 층간 삽입법과 직접 중합법으로 나눌 수 있다. 본 연구에서는 디알릴테레프탈레이트와 1,3-부탄디올을 단량체조 하여 알릴 에스터 예비 중합체를 합성하고, 점토를 이용하여 층간 삽입법과 직접 중합법으로 나노복합재를 제조하여 점토의 함량, 경화조건, 점토의 혼합 방법에 따른 특성을 분석하였다. 실리케이트 층간 거리는, 30B-점토를 이용하여 직접 중합법으로 제조하였을 때, 40$\AA$ 이상으로 가장 넓게 나타났다. 이는 유기화제의 작용기 (-OH)와 단량체가 실리케이트의 층 사이에서 에스터 교환 반응을 일으켜, 층간 거리가 증가하였기 때문이다. 또한 기계적 특성과 열적 특성 확인으로 점토의 분산 정도가 복합재의 물성 향상의 중요한 인자임을 확인할 수 있었다.

• Macromolecular Research
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• 제16권4호
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• pp.329-336
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• 2008

Core/shell ($\pm$)PS/(-)silica nanocomposite particles were synthesized by dispersion polymerization using an amphoteric initiator, 2,2'-azobis [N-(2-carboxyethyl)-2,2-methylpropionamidine] ($HOOC(CH_2)_2HN$(HN=) $C(CH_3)_2CN$=NC $(CH_3)_2C$(=NH)NH $(CH_2)_2COOH$), VA-057. Negatively charged (-6.9 mV) silica was used as the stabilizer. The effects of silica addition time and silica and initiator concentrations were investigated in terms of polymerization kinetics, ultimate particle morphology, and size/size distribution. Uniform hybrid microspheres with a well-defined, core-shell structure were obtained at the following conditions: silica content = 10-15 wt% to styrene, VA-057 content=above 2 wt% to styrene and silica addition time=0 min after initiation. The delay in silica addition time retarded the polymerization kinetics and broadened the particle size distribution. The rate of polymerization was strongly affected by the silica content: it increased up to 15 wt% silica but then decreased with further increase in silica content. However, the particle size was only marginally influenced by the silica content. The zeta potential of the composite particles slightly decreased with increasing silica content. With increasing VA-057 concentration, the PS microspheres were entirely coated with silica sol above 1.0 wt% initiator.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.223-224
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• 2003

Polyimides (PI) are widely used in applications ranging from microelectronics to aerospace. Due to their insulating nature, significant accumulation of electrostatic charge may result on their surface, causing local heating and premature degradation to electronic components or space structures. Over the past decade, several publications have been made in fabrication and charaterization of CNT nanocomposites [1,2]. (omitted)

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 추계학술발표회 논문집
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• pp.157-164
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• 2011