고분자의 내부압에 관한 연구

성용길,백우현 동국대학교 자연과학연구소 1988 자연과학연구 논문집 Vol.8 No.-

유리전이온도 위와 아래에서 고분자의 내부압에 대한 식을 고분자의 상태 방정식에 기초하여 유도하였다. 폴리스타이렌과 폴리옥시메틸스타이렌 등과 같은 고분자의 내부압을 계산하고 실험치와 비교하였다. 그 계산된 결과는 실험 데이터와 잘 일치하였다. An equation for internal pressure (Pi) of polymers above and below glass transition temperature has been derived on the basis of the equation of state for polymers. The internal pressures for polymers such as polystyrene and polyoxymethylstyrene are calculated and compared with the experimental values of the polymers. The calculated results are found to be in good agreement with the experimental data.

2-Hydroxyethyl Methacrylate와 5,6-Dihydro-4H-1,3-Oxazine 및 2-Phenyl-1,3,2-Dioxaphospholane의 Zwitterion 공중합에 관한 연구

成墉吉,白形基 동국대학교 1985 論文集 Vol.24 No.-

친수성 poly(2-hydroxyethyl methacrylate) (PHEMA)는 생체 적합성과 안전성이 있는 물질로 생의학적 적용을 하는 데 널리 사용되고 있으나 그 고분자의 기계적 성질과 혈액 적합성이 좋지 않은 것이 아직 개선되어야 할 문제점으로 남아 있다. 그 물질의 물성 및 순도의 문제점 등을 개선하기 위해서 2-hydroxyethyl methacrylate(HEMA)를 5, 6-dihydro-4H-1,3-oxazine(OZI) 및 2-phenyl-1, 3, 2-dioxaphospholane(ethylene phenylphosphonite, EPO)에 대해 촉매를 사용하지 않고 zwitterion 중간체를 경유하여 순수한 공중합체를 합성하였다. 합성된 공중합체들의 특성을 적외선 분광법, 핵자기 공명 분광법, 시차주사 열량계법 및 열무게 측정 분석법에 의해 확인하였고, 또한 그 공중합체들의 물에 대한 팽윤성도 연구 조사하였다. Hydrophilic poly(2-hydroxyethyl methacrylate) has been largely accepted as a biocompatible and stable material for biomedical applications. However, some of its relatively poor mechanical properties and blood compatibilities are still remained as problems to be improved. In order to improve its physical properties and purity problems, some pure copolymers of 2-hydroxyethyl methacrylate(HEMA) with, 5,6-dihydro-4H-1,3-oxazine(OZI) and 2-phenyl-1, 3, 2-dioxaphospholane(ethylene phenyl phosphonite, EPO) have been synthesized via zwitterion intermediates without catalysts. The synthesize copolymers were identified by infrared spectorscopy and nuclear magnetic resonance spectroscopy. the thermal properties of the copolymers were measured by differential scanning calorimetry and thermogravimetry. the swelling properties of the copolymers in water are also investigated.

Rutile 단결정의 굴절율 및 C-축 향위 측정에 관한 연구

성용길,이재봉 동국대학교 대학원 1973 大學院硏究論集-東國大學校 大學院 Vol.3 No.-

The refractive index of grown rutile single crystal is measured by the method of minimum deviation and the orientation of C-axis is determined from the results. The refractive index for ordinary-ray is ω=2.614, for extraordinary-ray ξ=2.866, the birefringence of rutile single crystal amount to 0.252 and the angle difference between bisecting pane of prism and optical C-axis Δ_1=1。9'36". These results are reasonable agreement with other literature.

Poly(2-hydroxyethyl methacrylate-co-γ-methacryloxypropyl triethyl silane) 및 Poly(2-hydroxyethyl methacrylate-co-γ-methacryloxypropylmethyl bistrimethyl siloxysilane)의 반응성과 열적 성질

성용길,정태화,이상영 동국대학교 1986 論文集 Vol.25 No.-

Hydrophilic poly(2-hydroxyethyl methacrylate) has been accepted as biocompatible material for medical applications. Some of its relatively poor physical property are still remained as problems to be improved. In order to improve its physical property, new copolymers of 2-nhydroxyethyl methacrylate(HEMA) with silane monomers have been developed and synthesized. The silane monomers are γ-methacryloxypropyl triethyl silane(MPTS) and γ-methacryloxypropyl methyl bistrimethyl siloxysilane(MPMBSS). The compositions of unreacted monomers in the copolymers were separated and determined by the intensity of each peak by gas chromatographic analysis. The monomer reactivity ratios determined by the Kelen-Tu¨dos method are as follows; r_1=0.80 and r_2=0.71 for poly(HEMA-co-MPTS), r_1=1.22 and r_2=0.21 for poly(HEMA=co-MPMBSS). The tendency of alternating copolymerization and the relative reactivty of MPTS and MPMBSS with HEMA were investigated. The Q and e values were also calculated by the Alfrey-Price equation. The synthesized monomers and copolymers were identified by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The thermal properties of the copolymers were also measured by thermogravimetry and differential scanning calorimetry.

Rutile 단결정의 굴절율 및 C-축 향위 측정에 관한 연구

성용길,이재봉 동국대학교 대학원 1973 연구논집 Vol.3 No.-

Poly(2-Hydroxyethyl Methacrylate-co-2-Methacryloxyethyl-1,1,1-Trifluoroacetate)의 합성 및 물성에 관한 연구

성용길,성대경 동국대학교 1987 論文集 Vol.26 No.-

Swollen or unswollen synthetic polymeric films are suitable for separation techniques such as hyperfiltration, ultrafiltration, dialysis, electrodialysis, and piezodialysis. They have also found major uses in biomedical problems(artificial kidney membranes, etc.), enzyme related processes, ion-exchange, dental and pharmaceutical applications(controlled release system). Poly (2-hydroxyalkyl methacrylate)s are being considered as useful materials for various membranes and medical applications. The radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with 2-methacryloxyethyl-1, 1, 1-trifluoroacetate (METFA) has been investigated to understand their reactivities and to improve the physical properties of homopolymer. The monomer METFA was synthesized by esterification of 2-hydroxyethyl methacrylate with 1,1,1-trifluoroacetic acid(TFA). Azobisisobutyronitrile (AIBN) was used as an initiator in the radical copolymerization of HEMA with METFA. The compositions of unreacted monomers were determined by the intensity of each peak by gas chromatographic analysis. The monomer reactivity ratios were determined by Kelen-Tu¨do~s method. The values of the reactivity ratios are r_1=2.35 and r_2=0.21 for the HEMA(1)-METFA(2) system. The values of Q and e factors calculated by Alfrey-Price equation are 0.29 and-0.64, respectively. The characterization of the copolymers has been carried out by FT-IR spectrophotometer and thermal analysis techniques. The thermal stability and melting temperature(Tm) of the copolymers were increased, as the amounts of hydrophilic HEMA in the copolymers increased. The enthalpic changes associated with endothermic transition were evaluted by differential scanning calorimetry. The activation energies of poly (HEMA-co-METFA) were evaluated from the thermogravimetric data by Freeman and Carroll method. The equilibrium water swelling quantities of the homopolymers and copolymers are also measured and discussed on the basis of hydrophobicity and hydrophilicity.

Acrylonitrile-Styrene 공중합체의 합성 및 열적성질에 관한 연구

양정성,오세찬,성용길 慶南大學校 附設 基礎科學硏究所 1989 硏究論文集 Vol.1 No.-

Ammonium peroxidisulfate was used as an initiator in the free radical polymerization of acrylonitrile. Benozyl peroxide was used as an initiator in the free radical polymerization of styrene and in the free radical copolymerization of styrene with acrylonitrile. The synthesized polymers and copolymers have been identified by FT-IR spectrophotometer. The thermal properties and glass transition temperature(Tg) of the polymers and copolymers were measured by differential scanning calorimetry and thermogravimetry. The activation energies of thermal decomposition for the polymers and copolymers were evaluated from the thermogravimetric data by Freeman and Carroll method.

Poly-β(1,4)-D-glucosamine-g-polyethyleneoxide의 합성 및 물성에 관한 연구

주상명,장광태,성용길 동국대학교 자연과학연구원 1995 자연과학연구 논문집 Vol.15 No.-

Poly-β(1,4)-D-glucosamine derived from poly-β(1,4)-N-acetyl-D-glucosamine by treating with alkaline solution has been reported to be a promising polymer not only in the chemical field but also in biomedical area. Poly-β(1,4)-D-glucosamine used in this experiment was seen about 93 percentage of degree of deacetylation by heterogeneous alkaline soultion. Poly-β(1,4)-D-glucosamine-g-polyethyleneoxide was synthesized by homogeneous method. Various molecular weights of polyethyleneoxide as a hydrophilic and flexible spacer were introduced to Poly-β(1,4)-D-glucosamine to produce Poly-β(1,4)-D-glucosamine-g-polyethyleneoxide. The synthesized copolymers are characterized by FT-IR, elemental analysis, thermogravimetric analyzer, and differential scanning calorimetry.

결정형태에 따른 β-H₂ Pc의 요오드 도핑 특성

허순옥,김영순,성용길 동국대학교 자연과학연구원 1995 자연과학연구 논문집 Vol.15 No.-

Metal free phthalocyanine(β-H2Pc) partially doped with iodine, β-H2Pc(I)x, has been made to improve photosensitizing efficiency of ZnO/β-H2Pc. The content of iodine dopant level(x) for β-H2Pc(I)x upon β-H2Pc crystal shapes was characterized as isotropic β-H2Pc(I)0.96 and needle β-H2Pc(I)0.16 by elemental analysis. Characterization of iodine-oxidized β-H2Pc were investigated by TGA (thermogravimetric analysis), SEM, UV-VIS, and Raman spectrum. These results suggest that the iodine dopings of β-H2Pc. The surface photovoltaic effect of ZnO/β-H2Pc in the visible region depends on largely photoconductivity with regard to shapes of β-H2Pc. That is, the surface photovoltage of ZnO/isotropic β-H2Pc was greater than ZnO/needle β-H2Pc at 670nm. The surface photovoltage of ZnO/isotropic β-H2Pc(I)0.96 was approximately 5 times greater than that of ZnO/isotropic β-H2Pc and ZnO/needle β-H2Pc(I)0.16 was 3 times more efficient than ZnO/needle β-H2Pc at 670nm. Therefore Iodine doping of β-H2Pc resulted in increase in photoconductivity of β-H2Pc and photovoltaic effect of ZnO/β-H2Pc in the visible region.

β-H₂Pc 결정형태에 따른 Iodine Doped β-H₂Pc/ZnO계의 광증감 효과

허순옥,김영순,성용길 동국대학교 자연과학연구원 1995 자연과학연구 논문집 Vol.15 No.-

For the dye sensitization of zinc oxide in the visible region, β-metal free phthalocyanine(β-H2Pc) have been adsorbed on zinc oxide powder. The adsorption properties of β-H2Pc on ZnO have been investigated by means of Raman and electron spin resonance(ESR) spectroscopy. On the basis of these observations, it has been found that β-H2Pc in ZnO/β-H2Pc system are molecular aggregates, keeping their characteristics with regard to shape of β-H2Pc. The ZnO/β-H2Pc(I)x has shown greater surface photovoltaic effect than ZnO/β-H2Pc, depending mainly upon shapes and iodine doping level(x) of β-H2Pc. To improve the photosensitizing efficiency of ZnO/β-H2Pc(I)x system, ZnO/β-H2Pc(I)x system has been dispersed in poly(9-vinylcarbazole)(PVCZ). As the result, the photovoltage of ZnO/β-H2Pc(I)x/PVCZ has observed to be greater than ZnO/β-H2Pc(I)x when they are excited at 670nm. The photovoltage of ZnO/β-H2Pc(I)x also depends on the iodine dopant levels. The improvement of the photovoltaic effect in the ZnO/β-H2Pc(I)x/PVCZ system compared to ZnO/β-H2Pc(I)x might be due to the hole-injection from the excited-state β-H2Pc into PVCZ.