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研究生: 洪珮瑄
Hung, Pei-Hsuan
論文名稱: 高分子聚合微粒降解之研究
Study of the Degradation of Glycerol-Based Polymeric Biodegradable Microparticles
指導教授: 王竹方
Wang, Chu-Fang
王潔
Wang, Jane
口試委員: 周更生
Chou, Kan-Sen
王清海
Wang, Tsing-Hai
學位類別: 碩士
Master
系所名稱: 原子科學院 - 生醫工程與環境科學系
Department of Biomedical Engineering and Environmental Sciences
論文出版年: 2018
畢業學年度: 106
語文別: 英文
論文頁數: 87
中文關鍵詞: 生物可降解柔珠環境馬來酸甘油高分子
外文關鍵詞: microbeads
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  • 塑膠的大量生產導致各式各樣的塑膠汙染物增加,而塑膠碎片對海洋的汙染在1970年代就開始受到關注,其 來源為大型塑膠垃圾降解後產生的微小碎片或是日常生活所用的清潔用品中所包含的柔珠。為解決第二種汙染源,許多國家已立法禁止塑膠柔珠用於日常清潔用品。本文欲利用生物可降解高分子製備微粒,取代被禁用的柔珠。本文選用聚甘油馬來酸酯(poly (glycerol maleate),簡稱PGM)作為合成材料,此材料可在水中快速降解,且成本將較其他可降解材料更為低廉。研究中採用溶劑揮發法 (Solvent evaporation methods)製備顆粒狀的PGM材料,透過此方法可以得到粒徑範圍為30± 13 μm 且分子量分布指數(Polydispersity Index,簡稱PDI)落在0.2到0.3的PGM 微粒。
    為確保此方法製備而成的微粒可以在水中被快速降解,製成後的微粒將以下列三種條件進行降解測試: (1)在不同的酸鹼值中進行降解,了解酸鹼度對PGM水解的影響。(2) 在去離子水及合成海水中進行降解,確保在高鹽度環境下依然可以快速水解。(3) 觀察在含有酵素環境中的降解情形,避免其在生物體內累積。其中PGM在鹼性 (pH 10) 條件下的降解速度最為顯著,只需不到兩小時的時間便可完全降解;而在酸性條件 (pH 4) 則較為緩慢,經一個月僅降解約60%。在鹼性條件下,有氫氧根離子作為水解反應的催化劑,其催化效果優於氫離子,使得PGM在pH 10的條件下降解極為快速。而在合成海水中進行降解,其速度較純水來得緩慢,約一個月的時間僅降解36%,反觀純水中的PGM微粒一個月已降解50%以上。鹽度被認為是導致此差異的重大因素,當鹽度增加會使水不易進入微粒中,使得水解反應僅在表面發生,導致材料降解速度較慢。PGM微粒在酵素水解實驗中僅需10天便可完全降解,而在兩周的酵素實驗中PLA ( polylactide ) 僅降解約2%,以此證明PGM的生物可降解特性優越於PLA。
    透過以上結果,可知PGM微粒很有潛力取代市售的柔珠產品,且PGM相較於其他可降解材料如PLA或PHAs更為便宜,更是適合用於取代目前市面上的生物可降解材料。


    Plastics are one of the most common pollutants in the ocean. The microplastic pollution has been a severe problem which causes environmental concerns since the 1970s. The sources of plastic microparticles can be classified as primary and secondary. Primary microparticles are plastics fabricated to be the microscopic size microbeads, which is often used in the personal care product. Secondary microparticles are the plastic fragments formed by the breakdown of large plastics. The primary plastic microparticles, microbeads, have been banned by many countries. In this study, to reduce the microparticle pollution in the aquatic system, poly (glycerol maleate) (PGM) is used to fabricate the alternative of microbeads due to its high degradability in the water and the relatively low cost compared to other biodegradable polymers.
    PGM microparticles are fabricated via solvent evaporation methods and the products are analyzed by Image J. Their average diameter and the PDI are around 30±13 and 0.2 to 0.3.
    Microparticles were tested in different water solutions, including buffer solution with different pH values, DI water, sea water and enzyme solution, to identify the degradability of PGM microparticles. They were sampled in the regular period and monitored by TOC analyzer, UV-Vis spectrum, microscopy, and SEM. These microparticles were completely degraded in 2 hours in alkaline solution (pH 10). In contrast, in the acidic solution (pH 4), 60 % of PGM microparticles were degraded in 30 days. This significantly different behavior was a result of that the base catalysis of hydrolysis was quicker than acid-catalysis. 50% more of PGM microparticles were degraded in the DI water in a month. However, only 36% of microparticles were degraded in synthetic sea water. The salinity was suspected to obstruct water penetrating into microparticles and slow down the degradation rate. For enzyme solution, microparticles were degraded in 10 days.
    This work aims to expand the application of PGM from films to microparticles. PGM is more affordable compared to other biodegradable polymers such as PLA and PHAs, and it is thought to have great potential for being the alternative to plastic microbeads.

    摘要 I ABSTRACT III 謝誌 V TABLE OF CONTENTS VI LIST OF FIGURES IX LIST OF TABLES XIV CHAPTER 1 INTRODUCTION 1 1.1 Background of the Study 1 1.2 Research Motivation 2 CHAPTER 2 LITERATURE REVIEW 4 2.1 Introduction to Microparticles 4 2.1.1 Introduction to Plastic Waste in the Oceans 4 2.1.2 Influence of Microparticles (Microplastic(MPs)) on Environment 6 2.1.3 Plastic Microbeads Ban 8 2.2 Alternatives to Microbeads 11 2.2.1 Nature Alternatives to Microbeads 11 2.2.2 Synthetic Alternative 11 2.2.3 Poly (glycerol maleate) (PGM): A Glycerol Base Polyester 14 2.3 Fabrication of Polymeric Particles 17 2.3.1 Polymerization of monomers 18 2.3.2 Solvent Evaporation Methods 19 2.4 Polyester Hydrolytic Degradation 21 2.4.1 Effect of pH Values on Hydrolytic Degradation 22 2.4.2 Effect of Ionic Strength on Hydrolytic Degradation 23 CHAPTER 3 MATERIALS AND METHODS 25 3.1 Instruments and Materials 25 3.1.1 Instruments 25 3.1.2 Materials 29 3.2 Fabrication of PGM Microbeads 31 3.2.1 Preparation of PGM Prepolymer 31 3.2.2 Microparticles Fabrication 32 3.3 Degradation of PGM Microparticles 34 3.3.1 Hydrolytic Degradation of Microparticles in Different pH Value 34 3.3.2 Degradation of PGM Microparticles in Deionized Water (DI water) and Sea Water. 35 3.3.3 Biodegradation in Enzyme Solution 36 3.3.4 ESI-MS 36 CHAPTER 4 RESULTS AND DISCUSSION 38 4.1 Fabrication of PGM Microparticles 38 4.1.1 Syringe Pump Injection Rate 39 4.1.2 The Stirring Speed via Fabrication 42 4.1.3 The Ratio of PGM and Acetone of the Polymer Solution 43 4.1.4 Change the Droplet Size with Different Tube Diameter 47 4-2 PGM Degradation 51 4.2.1 Influence of pH Value on Degradation 51 4.2.2 Degradation in Deionized Water (DI water) and Seawater 54 4-2-3 Degradation in Enzyme Solution 58 4.3 Mechanism of PGM Hydrolysis 60 4.3.1 Mechanism of PGM Hydrolysis in DI Water 60 4.3.2 Qualitative Analysis of Oligomer in the Medium via Immersing PGM in DI water 66 4.3.3 The Effect of pH Value on Degradation 69 CHAPTER 5 CONCLUSIONS AND FUTURE WORKS 74 5.1 Conclusions 74 5.2 Future Work 75 CHAPTER 6 REFERENCE 76 APPENDIX 85  

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