초록 ▼

기체투과 성능이 우수한 고분자 기체분리막을 얻기 위해서는 고분자 재료에 관한 연구와 분리막을 만드는 방법에 대한 연구가 같이 진행되어야 한다. 기체투과 성능인 기체투과도와 투과선택도를 고려해보면, 유리상 고분자 (glassy polymer)들이 고무상 고분자 (rubbery polymer)에 비해 기체투과도가 낮은 반면에 높은 투과선택도를 보여주고 있다. 특히 유리상 고분자중에서 polysulfone은 엔지니어링 플라스틱으로 기계적 물성이 우수하고 기체에 대한 투과선택성이 우수하여 기체분리막 소재로 가장 많이 사용되고 있다. 본 연

기체투과 성능이 우수한 고분자 기체분리막을 얻기 위해서는 고분자 재료에 관한 연구와 분리막을 만드는 방법에 대한 연구가 같이 진행되어야 한다. 기체투과 성능인 기체투과도와 투과선택도를 고려해보면, 유리상 고분자 (glassy polymer)들이 고무상 고분자 (rubbery polymer)에 비해 기체투과도가 낮은 반면에 높은 투과선택도를 보여주고 있다. 특히 유리상 고분자중에서 polysulfone은 엔지니어링 플라스틱으로 기계적 물성이 우수하고 기체에 대한 투과선택성이 우수하여 기체분리막 소재로 가장 많이 사용되고 있다. 본 연구에서는 막 소재로 널리 사용되고 있는 bisphenol-A polysulfone을 화학적으로 개질하여 목적물질로 삼아 투과도를 향상시킨 새로운 변형 폴리술폰계 기체분리막 소재를 개발하였다. 본 연구에서 제안한 방법을 간단히 기술해보면, polysulfone의 주쇄에 있는 방향족인 phenylene ring에 부피가 비교적 큰 치환기를 도입함으로써 고분자 사슬들이 막을 형성할 때 사슬과 사슬 사이의 packing을 저지시켜 주어 사슬과 사슬 사이에 비교적 작은 공간을 만들 수 있으며, 이러한 작은 공간의 생성으로 인해 투과하는 기체가 막을 통과하는데 비교적 수월하게 만들어 주어 투과도를 증가시키는 효과를 보고자 하였다. 또한 치환기가 도입됨에 의해 막의 기체에 대한 투과도와의 상관관계를 여러 가지 실험을 통해 명확히 규명을 하고자 하였다. 더 나아가 투과선택도가 우수한 integrally-skinned asymmetric membrane을 만들고자 하였다.

Abstract ▼

In this study, the effect of side-chain substituents was investigated on the gas permeability of polymers and the relationship between the structure and the gas permeability of polymers. Polysulfones were selected as a base materials because of its wide usage in gas separation membranes. Chemical re

In this study, the effect of side-chain substituents was investigated on the gas permeability of polymers and the relationship between the structure and the gas permeability of polymers. Polysulfones were selected as a base materials because of its wide usage in gas separation membranes. Chemical reaction was utilized to introduce various specific groups on the phenylene rings of polysulfones. The introduction of side-chain substituents has shown strong effect on the gas transport properties of polysulfones The permeability results of polysulfones modified with siIyl groups could be explained based on the structural characteristics of the silyl groups classified as follows. (1) the effect of trimethylsilyl (TMS) substitution, (2) the effect of degree of substitution (DS), (3) the role of spacer groups, (4) the size of substituents, and (5) the site of substitution. In general, all silylated polysulfones except BPA-PSF-DPS had higher permeabilities and lower selectivities for permanent gases tested, which is called a 'trade-off' trend and generally observed form the gas transport property study of polymeric membranes. TMS was observed more effective in increasing the gas permeability than any other silyl groups such as DMS and DPS although TMS was smaller in size than silyl group. In addition to the silyl groups, some other substituents had been introduced on the phenylene rings of polysulfones. From the measurements of the gas permeation, the following results were observed: (1) Asymmetrical substitution of small side groups on the phenylene rings of polysulfones decreased the gas permeability. (2) Polar groups such as hydroxyl or halogen decreased the gas permeability. (3) Azide and phosphorous groups decreased the gas permeability. From the gas transport study of polysulfones having various side groups, it could be concluded that the structural characteristics of modified polysulfones had strong and peculiar effects on the gas permeation as follows. (1) TMS was very efficient on increasing the gas permeability of polymers, even in the case of asymmetric substitution on the phenylene rings, (2) the gas permeability increased with the degree of substitution, (3) the spacer groups between the phenylene rings and TMS also showed significant effect on the gas permeability, (4) polar groups such as hydroxyl or halogen affected inversely the gas permeability, (5) the mobility of silyl groups seemed to have stronger effect on the gas permeability than the size of silyl groups, (6) the site of substitution affected the gas permeability, which could be attributed to the mobility effect. Among experimental observation given above, the last two terms are very significant contribution on the study of the gas separation membrane materials. So far, the structural effects of polymeric materials on their gas permeation properties have been interpreted based on the first four arguments. There have not been any trial on the effect of the mobility of polymer chains on the gas permeation. From the study of the gas permeation properties of modified polysulfones, BPA-PSF-TMS-e (EM3) was selected as a material for asymmetric membrane formation because of its excellent gas permeation characteristics. The integrally-skinned asymmetric membranes were prepared form EM3 as well as BPA-PSF for comparison using dry-wet phase inversion method, where the solution-casted films were first evaporated for a certain time period at 50℃ and RH < 10% and then the films were immersed into the water bath. The polymer concentration was increased with the evaporation time, which was believed to give integrally skinned asymmetric membranes with selectivity top-layer and porous sub-layer. The permselectivity for permanent gases was increased with the evaporation time although the gas permeance decreased. This confirmed the formation of the defect-free gas-selective layer top layer. The formation of gas-selective top layer was also confirmed by the scanning electron microscopy (SEM) analysis of the cross-sectional morphology of asymmetric membranes .

목차 Contents

• 제 1 장 서론...21
• 제 1 절 고분자 기체분리막...21
• 제 2 절 고분자 막의 기체투과...25
• 제 3 절 연구 개발의 목적...26
• 제 2 장 국내외 기술현황...29
• 제 3 장 연구개발수행 내용 및 결과...33
• 제 1 절 이론적 배경...33
• 제 2 절 실험...35
• 2.1 고분자 재료와 개질반응...35
• 2.2 분리막 제조와 투과도 측정...37
• 2.3 고분자 물성관찰...44
• 2.3.1 물리적 성질관찰...44
• 2.3.2 열적 성질 관찰...46
• 2.4 Solid-state NMR...46
• 2.5 비대칭막 제조 및 분석...48
• 제 3 절 결과 및 토의...49
• 3.1 고분자 구조와 기체투과도 상관관계...49
• 3.1.1 Silyl기를 갖는 m-PSF...49
• 3.1.2 다른 치환기를 갖는 m-PSF...71
• 3.2 비대칭막 제조...73
• 제 4 장 연구개발 목표 달성도 및 대여기여도...81
• 제 5 장 연구개발결과의 활용계획...83
• 제 6 장 참고문헌...85
• 부록...89