http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
백두현,지민호,이한섭,육지호,서승원,Baik, Doo-Hyun,Ji, Min-Ho,Lee, Han-Sup,Youk, Ji-Ho,Seo, Seung-Won 한국섬유공학회 2006 한국섬유공학회지 Vol.43 No.6
Segmented block copolyetherester (CPEE) solutions containing three kinds of nanoparticles were electro-spun and the resultant nanocomposite webs were characterized. Nano-sized clay, silica, and multi-walled carbon nan-otubes (MWNT) were used as nanoparticles and dichloromethane/trifluoro acetic acid (50:50, v/v) mixed solution was used as an electrospinning solvent. The FE-SEM analysis of the electrospun webs revealed that diameter of the nano-composite fibers was greater than that of pure CPEE. According to the FE-SEM results of the plasma-etched web, we knew that MWNT was aligned along fiber and silica particles were rather aggregated than being separated to the primary particles. DSC experiments indicated that electrospun web had higher melting temperature and heat of fusion than the film prepared from the same solution.
백두현,임수진,Baik Doo-Hyun,Im Su-Jin 한국섬유공학회 2006 한국섬유공학회지 Vol.43 No.3
Polyhydroxyamide, a precursor polymer to polybenzoxazole, was synthesized by low temperature polymerization of dihydroxybenzidine and isophthaloyl chloride. The polyhydroxyamide solution was electro spun under appropriate concentration, viscosity, electrical conductivity, voltage and tip collector distance. Electrospun polyhydroxyamide fibers were heated at the elevated temperature and converted to polybenzoxazole fibers. In this study we investigated the effects of the electrospinning factors, such as solution viscosity, concentration, and electrical conductivity on the fiber formation of polyhydroxyamide during electro spinning. The electrospun polyhydroxyamide nanofibers showed broader DSC endothermic peak as compared to film or powder samples, which was thought to be due to the large sur-face area of nanofiber web.
PTT, PBT, PBN 및 폴리테트라메틸렌에테르글리콜 구조를 갖는 세그먼트화 블록 코폴리에테르에스터 고무탄성체의 합성과 물성(I) -합성과 열적성질-
백두현,김해영,Baik, Doo-Hyun,Kim, Hae-Young 한국섬유공학회 2005 한국섬유공학회지 Vol.42 No.4
Segmented block copolyetheresters having three kinds of hard segments, i.e., poly(trimethylene terephthalate) (3GT), poly(butylene terephthalate) (4GT), poly(butylene naphthalate) (4GN) combined with poly(tetramethylene ether glycol) (PTMG) as a part of soft segment were synthesized with various hard segment contents. The number average molecular weights of PTMG selected were 1000, 2000, and 2900. The effects of hard segment content (HSC) and hard segment length (HSL) on the thermal properties of copolyetheresters were studied. Melting temperature $(T_m)$ was found to be a function of HSL for all the copolymers examined. Even at the very short HSL, 3GT and 4GN showed relatively high $T_m\;while\;T_m$ of 4GT decreased considerably. The 3GT hard segment showed highest hard segment crystallinity among the three, which implied that 3GT copolyetheresters had higher degree of phase separation and more stable crystalline phase in the copolyetherester elastomer than 4GT and 4GN.
폴리벤즈옥사졸계 고성능 나노복합체 섬유에 관한 연구(I) - 폴리히드록시아미드-클레이 나노복합체의 제조와 특성분석 -
백두현,이원옥,Baik, Doo-Hyun,Lee, Won-Ok 한국섬유공학회 2005 한국섬유공학회지 Vol.42 No.5
In the present study we investigated a clay nanocomposite based on polybenzoxazole (PBO) in order to get high performance PBO nanocomposite fibers. We synthesized polyhydroxyamide (PHA), a precursor polymer to PBO, by low temperature polymerization of dihydroxybenzidine and isophthaloyl chloride. Three kinds of clay dispersions were prepared by in-situ polymerization method, direct mixing of PHA and organo-clay, and mixing with sonication, respectively. X-ray diffraction experiment revealed that PHA-clay nanocomposite showed exfoliation in both direct mixing method and mixing with sonication method. On the other hand, a PHA-clay composite prepared by in-situ method showed no intercalation and exfoliation. TGA and DSC study revealed that the PHA-clay nanocomposites could cyclize at lower temperature compared with PHA. This implies that clay nanoparticles affect the thermal cyclization reaction of PHA lowering the cyclization temperature.
다중벽 탄소나노튜브를 함유한 Copolyamide 나노복합체의 제조와 물성
임재호,지민호,백두현,Lim, Jae-Ho,Jee, Min-Ho,Baik, Doo-Hyun 한국섬유공학회 2011 한국섬유공학회지 Vol.48 No.1
Copolyamide 66/6T/610 was synthesized by the condensation polymerization of polyamide 66, 6T, 610 salts. Copolyamide nanocomposites containing well-dispersed multi-walled carbon nanotubes (MWNTs) were prepared using a solution mixing method. The crystallinity increased with increasing MWNT content, suggesting that MWNT can help the copolyamide crystallize further. The copolyamide/MWNT nanocomposites also showed improved mechanical properties and electrical conductivity. Scanning electron microscopy of the fracture surfaces of the composite showed not only a uniform dispersion of MWNTs but also strong interfacial adhesion with the matrix, as evidenced by the presence of many broken but strongly embedded carbon nanotubes in the matrix.
폴리히드록시아미드 섬유의 제조와 열처리에 따른 구조-물성 상관관계(I) -다양한 고화조건에 따른 고화거동-
강찬솔,지민호,백두현,Kang, Chan Sol,Jee, Min Ho,Baik, Doo Hyun 한국섬유공학회 2013 한국섬유공학회지 Vol.50 No.4
Polyhydroxyamide (PHA) was synthesized using low temperature solution polymerization of 3,3'-dihydroxybenzidine (DHB) and isophthaloyl chloride (IPC) in N,N-dimethylacetamide (DMAc). In order to study wet-spinning of PHA fibers, the diffusion property of DMAc in various coagulants and the effect of coagulation bath temperature were evaluated. The initial diffusion rate of DMAc, and the SEM images and mechanical properties of PHA fibers, demonstrated that the coagulation in ethanol at $20^{\circ}C$ was the most optimal among all the conditions examined. The tensile strength and initial modulus of PHA fibers increased, while its breaking strain decreased with increasing spin draw ratio (SDR). The wide-angle X-ray diffraction (WAXD) experiment revealed that the crystallinity of PHA fibers increased with increasing SDR. The process-structure-property relationship among PHA fibers under various coagulation conditions was also investigated.
방향족 폴리히드록시아미드의 합성과 열적 고리화 거동(I) -벤젠고리 치환구조의 영향-
지민호,이주용,백두현,Jee, Min Ho,Lee, Ju Yong,Baik, Doo Hyun 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.5
We have synthesized polyhydroxyamides (PHAs), a possible precursor which could be converted to polybenzoxazole (PBO) through a thermal cyclization reaction, by low temperature solution polymerization of 3,3'${\AE}$-dihydroxybenzidine with terephthaloyl chloride or isophthaloyl acid. Structural characteristics, solubility, thermal cyclization, and thermal decomposition of the PHAs were investigated by the FT-IR, DSC and TGA in order to understand the effect of chemical structure of acyl chlorides on the thermal properties of PHAs. The FT-IR study reveals that two types of PHAs can cyclize on heating and be transformed into PBOs. The meta-type PHA (m-PHA) shows better solubility in N,N-dimethylformamide and dimethyl sulfoxide than the para-type PHA (m-PHA). DSC and TGA results demonstrate that the m-PHA can cyclize at lower temperature than p-PHA, which is due to the difference in activation energy of thermal cyclization between m-PHA and p-PHA. TGA results reveal that the p-PHA has better thermal stability than m-PHA while in flame.
MWNT와 Graphite 전도성 나노입자를 함유한 폴리우레탄 하이브리드 나노복합체의 기계적 물성 및 전기적 특성 평가
강찬솔,지민호,백두현,Kang, Chan Sol,Jee, Min Ho,Baik, Doo Hyun 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.3
The synergistic effects of multi-walled carbon nanotubes (MWNT) and graphite on the structural features and mechanical and electrical properties of polyurethane (PU) nanocomposites were investigated as functions of filler content. SEM images of the PU/hybrid nanocomposite exhibit that the MWNTs and graphite are dispersed well in the PU matrix and form an interconnected network structure. Accordingly, the tensile strength and strain-at-break of the PU/hybrid nanocomposites were much higher than those of the PU/MWNT and PU/graphite nanocomposites at the same filler content. In addition, it is found that the PU/hybrid nanocomposite containing 1.25 wt% MWNTs and 1.25 wt% graphite shows the electrical conductivity of $1.2{\times}10^{-4}S/cm$, which is higher by three orders than that of PU/graphite nanocomposite containing 20.0 wt% graphite. The highly improved mechanical and electrical properties of the PU/hybrid nanocomposite are thought to be due to the interconnected network structure of MWNTs and graphite in the PU matrix.