Design and Mechanism of Bio-Based Disulfide-Containing Poly(urethane-urea) Elastomers for Robust, Self-Healing, and Multi-Path Degradation : Bio-based Self-healing Poly(urethane-urea) with Multi-degradation Rute
견고성, 자가 치유성 및 다중 분해 경로를 갖는 바이오 기반 이황화물 함유 폴리(우레탄-우레아) 엘라스토머의 설계 및 메커니즘
- 주제(키워드) Self–healing , Poly(urethane–urea) , Disulfide bond , Multi–pathway degradation , Bio–based macro–diol
- 발행기관 서강대학교 일반대학원
- 지도교수 박제영
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 박사
- 학과 및 전공 일반대학원 화공생명공학과
- 실제URI http://www.dcollection.net/handler/sogang/000000082457
- UCI I804:11029-000000082457
- 본문언어 영어
- 저작권 논문은 저작권에 의해 보호받습니다.
초록(요약문)
The persistent use of petroleum-derived plastics continues to raise serious environmental concerns due to their durability and limited end -of-life options. Here, we report a bio-based polyurethane urea elas tomer that simultaneously achieves high mechanical strength (36 MP a), autonomous self-healing with efficiencies up to 98%, and on-dem and multi-pathway degradability. These combined properties arise fro m a synergistic molecular architecture incorporating aromatic disulfide units and urea linkages. The aromatic disulfide building block provides a rigid conjugated backbone that enhances thermal and mechanical sta bility, while its dynamic S–S bonds undergo rapid exchange at mild te mperatures, enabling efficient self-healing. Urea linkages further intro duce dual hydrogen-bond donors, generating a stronger and more dir ectional supramolecular network than urethane linkages and thereby i mproving cohesion and toughness. In addition, ester-rich bio-based p olyols introduce enzymatically cleavable segments into the polymer ba ckbone. This integrated structure effectively overcomes the conventio nal trade-off between robustness, dynamic functionality, and degradab ility. The resulting elastomer exhibits outstanding mechanical performa nce, more than 90% UV-induced healing at ambient temperature withi n 24 h, and reliable responsiveness to multiple degradation triggers. U nder reductive conditions at 37 ℃, the elastomer shows more than 9 9% mass loss within 4 d; under UV irradiation, clear photodegradation behavior is observed; and under enzymatic exposure, the material und ergoes more than 15% mechanical property reduction after 21 d. The se results highlight a versatile and sustainable design strategy for cre ating strong, adaptive, and environmentally degradable polyurethane ur ea materials. Keywords: Self–healing; Poly(urethane–urea); Disulfide bond; Multi–pathway degradation; Bio–based macro–diol
more목차
List of Contents iv
List of Figures viii
List of Tables xii
List of Abbreviations xiii
Abstract xv
Chapter 1.
Introduction 1
1.1. Background and Challenges in Sustainable Polymer Materials · 1
1.1.1. Environmental Pollution of Plastic 1
1.1.2. Limitations of Current Biodegradable Plastics and The
Need for a New Degradation Mechanism 3
1.1.3. Limitations of Conventional PU/PUU Systems and
Strategies for Sustainable Design 5
1.2. Self-Healing Polymers as a Sustainable Strategy to Mitigate
Plastic Pollution 8
1.2.1. Disulfide Bonds as Dynamic Covalent Motifs for
Self-Healing PUU 9
1.2.2. Disulfide Metathesis and Its Electronic Origin 10
1.2.3. Applications of Disulfide-Based Dynamic Polymer
Networks 12
1.3. Multi-Pathway Degradation as a Complementary Strategy 14
1.3.1. Hydrolytic and Enzymatic Degradation 15
1.3.2. Reductive Degradation of Disulfide Bonds 17
1.3.3. Photo-Induced Degradation via Radical-Mediated Pathways 19
1.4. Multi-Pathway Degradation as a Complementary Strategy 21
Chapter 2.
Experiment 24
2.1. Materials 24
2.2. Synthesis of Disulfide-Based Bio-Derived PUU Material 25
2.2.1. Preparation for Cystamine 25
2.2.2. Synthesis of Bio–based Disulfide Macro–diols 26
2.2.3. Synthesis of Degradable Self–healing PUUs 27
2.3. General Characterization of PUU 28
2.3.1. Structural Analysis of PUU 28
2.3.2. Characterization of Hydroxyl Value Titration 29
2.3.3. Mechanical and Thermal Properties Test 31
2.3.4. Measurement of Crosslink Density 33
2.3.5. Heat and UV, Mechanical Self–healing Properties Test 34
2.4. Degradation Behavior of Degradable Self–healing PUUs 36
2.4.1. Enzymatic Degradation Test Using Lipase 36
2.4.2. UV-Induced Degradation Test 37
2.4.3. Reduction-Induced Degradation Test Using DTT 38
Chapter 3.
Results and Discussion 39
3.1. Analysis of Bio-based Macro-diols 39
3.1.1. CL/GA Ratio Optimization 39
3.1.2. Various Initiator Control 45
3.2. Analysis of PUUs Different Urethane-Urea Bonding Ratio · 49
3.2.1. Structural Analysis 49
3.2.2. Mechanical and Thermal Properties 54
3.3. Analysis of PUUs Different Chain Extender 57
3.3.1. Structural Analysis 57
3.3.2. Mechanical and Thermal Properties 61
3.3.3. Self-healing Properties 69
3.3.4. Rheological Properties 73
3.3.5. Cooperative Disulfide Dynamics in Soft and Hard Domains of PUU Elastomers 76
3.4. Various Degradation Properties Test 79
3.4.1. Reductive Degradation 79
3.4.2. UV-induced Degradation 83
3.4.3. Enzymatic Degradation 87
Chapter 4. Conclusion 91
Chapter 5. Reference 93
