유/무기 층상 실리케이트 하이브리드 막의 제조 및 물성 = Preparation and physical property of organic/inorganic layered silicate hybrid membranes

다국어 초록 (Multilingual Abstract)

Polymer/layered silicate nanocohybrids(PLSNs) are new types of materials, based on clays usually rendering hydrophobic property through ion exchange of the sodium interlayer cation with an onium cation. It could be prepared from various synthetic routes comprising exfoliation adsorption, in situ intercalative polymerization and melt intercalation.
The whole ranges of polymers are being used, i.e. thermoplastics, thermosets and elastomers as a matrix. Two types of structures may be obtained, namely the intercalated nanohybrids of which the polymer chains are sandwiched in between silicate layers and the exfoliate nanohybridtes of which the separated, individual silicate layers are more or less uniformly dispersed in the polymer matrix. This new family of materials exhibits enhanced properties at a very low filler level, usually lower than 5wt.% , such as increased mechanical properties, an increase in thermal stability and gas barrier properties and good flame retardancy. Gas permeability through the PLSNs films decreased due to the increased tortuosity made by intercalation or exfoliation of clay in the polymer.
In this study, polymer-clay hybrid films were prepared by melt intercalation method with internal mixer with NBR, ionomer, and SEBS(styrene-ethylene-butylene-styrene) as polymer and Cloisite？Na+, Cloisite？15A, Cloisite？20A, Cloisite？30B of Southern Clay Product as clay.
Clay was intercalated or exfoliated by the polymer and confirmed by X-ray diffraction method. D-spacing of the characteristic peak from MMT plate in WAXD was moved and diminished.
Mechanical and thermal properties of the NBR-clay hybrid membranes were not changed with clay content. Mechanical and thermal properties of ionomer-clay hybrid and SEBS-clay hybrid membranes increased with clay . The clay acts as a heat barrier and assists in the formation of char after thermal decomposition as well.
Gas permeability of O2, CO2 and N2 of polymer-clay hybrid films was investigated. Gas permeability of hybrid membranes decreased in the order of CO2 > O2 > N2. The gas barrier property of hybrids with clay are better than that of pure polymers, hybrids with CloisiteⓇ 15A as clay showed the best barrier property among the hybridses. So gas permeability through the polymer-clay hybrid films decreased due to the increased tortuosity made by intercalation of clay in polymer.

목차 (Table of Contents)

• 1. 서 론 1
• 2. 이론적 배경 6
• 2.1 층상 실리케이트의 구조 6
• 2.2 유/무기 층상 실리케이트 하이브리드 막의 구조 7
• 2.3 유/무기 층상 실리케이트 하이브리드 막의 구조 14
• 2.3.1 중합법 14
• 2.3.2 용액법 15
• 2.3.3 용융삽입법 16
• 2.4 유/무기 층상 실리케이트 하이브리드 막의 특징 17
• 2.4.1 기계적 특성 17
• 2.4.1.1 인장특성의 영향 17
• 2.4.1.1.1 탄성율(Young's modulus) 17
• 2.4.1.1.2 응력(Stress at break) 26
• 2.4.1.1.3 신율(Elongation at break) 28
• 2.4.2 열적 안정성 33
• 2.4.3 Gas barrier 특성 35
• 3. 실 험 42
• 3.1 재료 42
• 3.2 고분자-clay 하이브리드 막의 제조 42
• 3.2.1 NBR-clay 하이브리드 막의 제조 42
• 3.2.2 Ionomer-clay 하이브리드 막의 제조 46
• 3.2.3 SEBS-clay 하이브리드 막의 제조 47
• 3.3 분석 47
• 3.3.1 XRD 분석 47
• 3.3.2 열적 특성 분석 47
• 3.3.3 기계적 특성 분석 48
• 3.3.4 기체투과 특성 분석 49
• 4. 결과 및 고찰 50
• 4.1 고분자-clay 하이브리드 막의 구조 분석 50
• 4.1.1 NBR-clay 하이브리드 막의 구조 분석 50
• 4.1.2 Ionomer-clay 하이브리드 막의 구조 분석 55
• 4.1.3 SEBS-clay 하이브리드 막의 구조 분석 62
• 4.2 고분자-clay 하이브리드 막의 열적 특성 69
• 4.3 고분자-clay 하이브리드 막의 기계적 특성 80
• 4.3.1 인장강도 및 모듈러스 80
• 4.3.2 경도 84
• 4.3.3 밀도 88
• 4.4 고분자-clay 하이브리드 막의 기체 투과 특성 92
• 5. 결 론 104
• 6. 참 고 문 헌 106
• ABSTRACT 116