Duck Kun Hwang
Yonsei University
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Featured researches published by Duck Kun Hwang.
Materials Letters | 2002
Kyeong Taek Jung; Duck Kun Hwang; Yong Gun Shul; Haksoo Han; W.S Lee
Abstract Isotactic polyacrylonitrile (PAN) has been prepared by using a zeolite as a host. After introduction of acrylonitrile monomers, they were subsequently polymerized with radical initiators in Na–Y and Na–β zeolite channels, followed by extraction with hydrofluoric acid. 13C-NMR results show that the isotacticity of extracted PAN is higher than that of bulk PAN prepared under the same reaction conditions and is also affected by the pore structure of host. Thermal and physical properties of extracted PAN were also investigated using GPC, DSC and XRD.
Carbon letters | 2014
Sua Choi; Duck Kun Hwang; Heon Lee
Blends of poly(vinyl alcohol) (PVA), polyethyleneimine (PEI), and graphene oxide (GO) were prepared by solution casting method. Calorimetric thermal properties of the blends were investigated. The Tgs of PVA/PEI blends were higher than the Tgs of either of the component polymers at low concentrations of PEI. These abnormal increases of Tgs may be due to the negative entropy of mixing which is associated with strong hydrogen bonding between PVA and PEI. The degree of depression of s was not reduced by the negative entropy of mixing, since strong hydrogen bonding also causes an increase in the magnitude of negative c between PVA and PEI. The Tg of PVA was increased significantly by adding 0.7 wt.% GO into PVA. The magnitude of negative c was increased by adding GO into the blends of PVA and PEI
Polymer-plastics Technology and Engineering | 2014
Duck Kun Hwang; Heon Lee; Kyeongseok Oh
Criteria of cycle time include metering, closing a mold, packing, holding, cooling, opening a mold and ejecting. Interestingly, metering time was found relatively lengthy in the composite of glass fiber (GF)-reinforced syndiotactic polystyrene (sPS) during injection molding. It was motivated by the ideas that analyzing dynamic thermal property may provide the correlation with metering time because differential scanning calorimeter does not fully provide dynamic thermal property. We created new measuring system to examine thermal behavior in the presence of pressure loading. The method was very effective to determine the melting rate of thermoplastics in the presence of pressure loadings.
Topics in Catalysis | 2008
Hyun-Jong Kim; Myung-Keun Han; Sang-Min Lee; Duck Kun Hwang; Yong Gun Shul
Polymer Engineering and Science | 2014
Duck Kun Hwang; Heon Lee; Hyun Jong Kim; Yong Gun Shul; Kyeongseok Oh
Industrial & Engineering Chemistry Research | 2013
Duck Kun Hwang; Yong Gun Shul; Kyeongseok Oh
Journal of Sol-Gel Science and Technology | 2004
Duck Kun Hwang; Hyun Jong Kim; Hak Soo Han; Yong Gun Shul
Journal of Alloys and Compounds | 2015
Ho-Nyun Lee; Chi-Ho Shin; Duck Kun Hwang; Haekyoung Kim; Kyeongseok Oh; Hyun-Jong Kim
Iranian Polymer Journal | 2014
Duck Kun Hwang; Kyeongseok Oh
Topics in Catalysis | 2008
Hyun-Jong Kim; Myung-Keun Han; Sang-Min Lee; Duck Kun Hwang; Yong Gun Shul