공중합에 의해 제조된 온도 및 pH 응답성 하이드로젤의 체적전이온도, 팽윤거동 과 방출특성 변화 = Variation in Volume Transition Temperature, Swelling Behavior and Release Property of Temperature and pH-Responsive Hydrogels by Copolymerization

다국어 초록 (Multilingual Abstract)

Temperature and pH-responsive hydrogels were prepared with the combination of various hydrophilic and hydrophobic monomers. N-isopropylacrylamide (NIPAAm) and acrylamide (AAm) were chosen as the hydrophilic monomer and n-butoxymethylacrylamide (nBMA) was chosen as the hydrophobic monomer. Poly(ethylene glycol) methyl ether methacrylate (PEG) was chosen as the macromonomer for the hydrophilic graft. Acrylic acid (AAc) was chosen as the monomer for preparation of the pH stimuli-responsive hydrogel. 2,4-Dichlorophenoxyacetic acid was chosen as the herbicide loaded into hydrogel. Hydrogels were prepared by photopolymerization. Volume transition, swelling behavior and release property were studied for these hydrogels. Volume transition and swelling behaviors were fast and thermally reversible. Poly(NIPAAm) hydrogel showed the sensitivity to the thermal stimuli at around 30℃ with a large volume change. The transition temperature was controlled by incorporating other monomers. nBMA was incorporated in a proper composition for the preparation of thermal stimuli-sensitive hydrogels which had a sharp volume transition temperature around 15℃. The hydrogels which have AAc as one of their components showed very different behavior depending on the pH. Volume transition temperature, degree of swelling, and release rate were varied significantly depending on the content of comonomer, graft, and crosslinker.

목차 (Table of Contents)

• 목차
• 1. 서론 = 1
• 2. 이론적 배경 = 2
• 2.1. Hydrogel = 2
• 2.1.1. Thermo-Sensitive hydrogel = 3
• 2.1.2. pH sensitive hydrogel = 7
• 2.2. Volume Phase Transition and Releated Phenomena of Polymer Gels = 9
• 2.2.1. Gel의 특성 = 9
• 2.3. Fundemental Interactions for Volume Phase Transition of Gels = 13
• 2.3.1. Van der Waals Interaction = 15
• 2.3.2. Hydrophobic interaction = 17
• 2.3.3. Hydrogen bonding = 17
• 2.3.4. Electrostatic Interaction = 18
• 2.4. Environment Sensitive Gels = 21
• 2.4.1. Thermo-Sensitive Gels = 21
• 2.4.2. Ion and pH Sensitive Gels = 21
• 2.4.3. Light Sensitive Gels = 22
• 2.4.4. Biochemically Sensitive Gels = 23
• 3. 실험 = 25
• 3.1. Materials = 25
• 3.2. Hydrogel 제조 = 25
• 3.3. 팽윤도 측정 = 26
• 3.4. DSC에 의한 흡열거동 측정 = 26
• 3.5. 2,4-D 방출량 측정 = 26
• 4. 결과 및 고찰 = 28
• 4.1. Hydrogel의 제조 및 특성 = 28
• 4.2. PEG 그래프트 변성 Hydrogel = 31
• 4.3. 가교제의 함량에 따른 변화 = 35
• 4.4. AAc 그래프트된 변성 Hydrogel = 37
• 4.5. 2,4-D 방출 특성 = 41
• 5. 결론 = 46
• 참고문헌 = 47
• ABSTRACT = 50