연료전지용 폴리(페닐렌 옥사이드–피페리디늄) 및 Fumion@FAA3 블렌딩 음이온교환막의 합성 및 특성 분석 = Synthesis and Characterization of Poly(phenylene oxide–piperidinium) and Fumion@FAA3 Blended Anion Exchange Membranes for Fuel Cell Applications

다국어 초록 (Multilingual Abstract)

In the field of hydrogen fuel cell technologies, proton exchange membrane fuel cells (PEMFCs) are employed due to their superior thermomechanical-chemical stability and ion conduction property. Nevertheless, there are obstacles to PEMFC commercialization, such as lower durability in crossover and acidic conditions and cost issues because of the requirement for platinum catalysts. Anion exchange membrane fuel cells (AEMFCs), that work in alkaline environments, are drawing interest as a solution to these problems. Even though AEMFCs are less expensive than non-precious metal catalysts, there are still problems, such as poor ionic mobility because of the small size of the OH- ions and problems with chemical resistance owing to the degradation of polymer structures in alkaline environments. These are being investigated using a variety of methods, such as mixing, coating, composite production, functional group modification, and polymer structure design.
In this study, to enhance the ion conductivity and physical properties of AEM, quaternized poly(phenylene oxide) (QPPO) was synthesized using poly(phenylene oxide)-based polymers as starting materials via polymer bromination and the Menshutkin reaction. Commercially available anion exchange membrane material Fumion was blended to produce FAQP-x membranes with varying contents (5, 10, 15, 20 wt%), and the blending effect was verified by comparison with the QPPO membrane.
The structure of the synthesized polymers was confirmed via ¹H-NMR and FT-IR analysis, verifying the successful benzylic bromination of BrPPO and the quaternization reaction of QPPO. The membrane surface structure was observed using FE-SEM and AFM, and the potential for ion transport channel formation was confirmed via microphase separation. Thermal stability was evaluated through TGA analysis.
The evaluation of membrane properties (water absorption rate, swelling rate, IEC) showed that IEC improved with increasing Fumion content, with FAQP-15% exhibiting the highest IEC (2.12 meq g⁻¹). Ion conductivity measurements also showed FAQP-15% exhibited the highest conductivity at 58 mS cm⁻¹ at 90°C, a value significantly improved compared to FAA3. Furthermore, in the alkaline stability evaluation, FAQP-15% demonstrated the ability to maintain conductivity under long-term conditions, suggesting it maintains structural stability even in highly alkaline environments.
These results demonstrate that blending Fumion into PPO-based polymer systems is an effective strategy for enhancing the conductivity and properties of AEMs. FAQP-15% holds sufficient potential as a candidate anion exchange membrane for AEMFCs.

목차 (Table of Contents)

• List of tables ⅳ
• List of figures ⅳ
• Abstract ⅵ
• 제 1장. 서 론 1
• 1. 1. 온실가스감축을 위한 노력과 연료전지 1
• 1. 2. 연료전지의 원리 3
• 1. 3. 연료전지의 원리 5
• 1. 4. 알칼리 고분자 전해질 연료전지 9
• 1. 5. 고분자전해질음이온교환막(anion exchange membrane) 12
• 제 2장. 실험 14
• 2. 1. 시약 및 재료 14
• 2. 2. 실험 방법 14
• 2. 2. 1. 브로민화 poly(phenylene oxide) (BrPPO) 합성 14
• 2. 2. 2. 4차화 된 폴리(페닐렌 옥사이드)(QPPO) 합성 14
• 2. 2. 3. QPPO, FAQP-x 제막 15
• 2. 2. 4. QPPO, FAQP-x의 Br-의 OH- 치환 15
• 2. 3. 특성 분석 17
• 2. 3. 1. Proton nuclear magnetic resonance (1H-NMR) 17
• 2. 3. 2. Fourier-transform infared spectroscopy (FT-IR) 17
• 2. 3. 3. 접촉각 측정(Contact angle) 17
• 2. 3. 4. 함습률(water uptake, WU) 17
• 2. 3. 5. 팽윤율(swelling ratio, SR) 18
• 2. 3. 6. 이온교환용량(Ion Exchange Capacity, IEC) 18
• 2. 3. 7. Field emission scanning electron microscope (FE-SEM) 19
• 2. 3. 8. Atomic force microscopy (AFM) 19
• 2. 3. 9. Universal testing machine (UTM) 19
• 2. 3. 10. Ion conductivity 19
• 2. 3. 11. Alkaline stability 20
• 제 3장. 결과 및 고찰 21
• 3. 1. BrPPO, QPPO 및 FAQP-x 제조 및 막 제막 21
• 3. 2. PPO, BrPPO, QPPO 및 FAQP-x의 화학구조 분석 24
• 3. 3. 열적 특성 28
• 3. 4. 접촉각 측정(Contact angle), 함습률(water uptake, WU), 팽윤율(Sswelling ratio, SR), 이온교환용량(ion exchange capacity, IEC) 30
• 3. 5. 형태학 분석 37
• 3. 6. 기계적 특성 39
• 3. 7. 이온전도도 41
• 3. 8. 알칼리 안정성 44
• 3. 9. 단일전지 성능 평가(Single Cell Performance Evaluation) 47
• 제 4장. 결론 49
• 참 고 문 헌 50