臺灣博碩士論文加值系統

作為一種新型的積層製造技術，3D列印技術在各個領域蓬勃發展。與傳統的製造技術不同，3D列印技術具有用戶自訂的特點，以此避免了高昂的模具。聚胺脂 (polyurethane, PU) 作為一種高性能的材料備受關注。水性PU離聚物是綠色的、環境友好的高分子，但是通常PU的水分散液黏度太低，無法直接3D列印。在本研究中，通過在合成過程中加入纖維素奈米纖絲 (cellulose nanofibrils, CNFs)，成功製備出可直接列印的PU複合物。通過調控PU製備過程中加入的中和劑的量，可以有效改變最終PU/CNF複合分散液的黏度。流變學分析表明複合墨水有著優異的列印性。TEM圖像揭示了，借助物理化學多種鍵接，CNFs穿過多個PU奈米粒子形成串燒的結構，這一結構成功提高了PU/CNF複合分散液的黏度。3D列印後的PU/CNF支架有著優異的結構保真度和穩定性。同時，PU/CNF支架的壓縮模量遠高於通過加入增稠劑 (PEO) 列印的支架。在引入CNFs後，PU的體外降解速率提高了3倍。纖維母細胞在3D列印的支架中保持活性與增殖超過一周。PU/CNF支架將會有著各種各樣的應用，特別是在生物醫用領域。此外，CNF與PU之間的相互作用力提供了一種新型的、獨一無二的方法去調整水性PU分散液的黏度，以至於可以直接3D列印。

3D printing technology has been booming in various fields as a new type of layer-by-layer additive manufacturing technology. Unlike traditional manufacturing techniques, 3D printing has the advantage of customization and does not require expensive molds. Polyurethane (PU) has attracted attention as high performance materials. Waterborne PU ionomers are green, eco-friendly polymers but the viscosity of PU dispersion is generally too low for direct 3D printing. In the study, printable PU composites were successfully prepared by introducing cellulose nanofibrils (CNFs) during the synthesis of PU. The viscosity of the PU/CNF composite dispersion was effectively regulated by the amount of neutralizing agent in preparing anionic PU. Rheological measurements supported the good printability of the composite ink. TEM images revealed that CNFs linked multiple PU nanoparticles to form a ‘skewer’ structure through the physical and chemical interaction force, which successfully increased the viscosity of PU/CNF water dispersion. PU/CNF scaffolds were 3D printed from the composite ink with excellent pattern fidelity and structure stability. Meanwhile, the compression modulus of PU/CNF scaffolds was much higher than that of scaffolds printed with the common viscosity enhancer (PEO). The degradation rate of PU increased three times after the introduction of CNFs. Fibroblasts kept proliferating in the 3D printed PU/CNF scaffolds for more than a week. The printed PU/CNF composites may have various applications particularly in the biomedical field. Moreover, the interaction between CNF and PU may offer a novel and unique way to tune the viscosity of waterborne PU dispersion for direct 3D printing.

致謝 I
摘要 II
Abstract III
目錄 V
圖目錄 XI
表目錄 XIII
第一章 文獻回顧 1
1.1. 生物醫用材料 1
1.1.1. 金屬醫用材料 1
1.1.2. 非金屬醫用材料 1
1.1.3. 複合材料 3
1.2. 高分子奈米複合材料 4
1.2.1. 高分子與金屬奈米複合材料 5
1.2.2. 高分子與無機非金屬奈米複合材料 5
1.2.3. 高分子與高分子奈米複合材料 6
1.3. 聚胺脂材料 (polyurethane) 7
1.3.1. 油性聚胺脂材料 8
1.3.2. 水性聚胺脂材料 8
1.3.3. 水性聚胺脂材料的合成 9
1.4. 水性聚胺脂奈米複合材料 11
1.5. 三維列印 (three-dimensional printing, 3D printing) 12
1.6. 纖維素 (cellulose) 及其複合材料 13
1.6.1. 奈米纖維素 (nanocellulose) 13
1.6.2. 奈米纖維素與聚氨脂複合材料 14
1.7. 研究動機 15
第二章 研究方法 17
2.1. 研究架構 17
2.2. 纖維素奈米纖絲 (cellulose nanofiber, CNF) 的製備與表徵 19
2.2.1. CNF的製備與改質率的測定 19
2.2.2. 穿透式電子顯微鏡 (transmission electron microscopy, TEM) 20
2.2.3. 掃描電子顯微鏡 (scanning electron microscope, SEM) 20
2.3. 水性生物可降解聚胺脂 (waterborne biodegradable polyurethane, PU) 的製備與表徵 21
2.3.1. PU的製備 21
2.3.2. 動態光散射 (dynamic light scattering, DLS) 分析 21
2.4. PU/CNF複合薄膜的製備與表徵 23
2.4.1. PU/CNF複合物的多種製備方式 23
2.4.2. PU/CNF複合薄膜的製備 24
2.4.3. 熱性能分析 24
2.4.4. 拉伸試驗 24
2.4.5. 親疏水性 25
2.5. PU/CNF複合墨水的製備與表徵 25
2.5.1. PU/CNF複合墨水的製備 25
2.5.2. 流變學分析 (rheology measurement) 25
2.5.3. 穿透式電子顯微鏡 (transmission electron microscopy, TEM) 26
2.6. 3D列印製備PU/CNF和PU/PEO支架 (scaffold) 26
2.6.1. PU/PEO複合物的製備 26
2.6.2. 3D列印製備複合支架 26
2.6.3. 紫外光譜儀 (ultraviolet spectrograph, UV) 分析 27
2.7. 支架物理化學性能表徵 27
2.7.1. 掃描電子顯微鏡 (scanning electron microscope, SEM) 27
2.7.2. 動態熱機械分析 (dynamic thermomechanical analysis, DMA) 27
2.7.3. 體外降解實驗 28
2.8. 組織工程實驗 28
2.8.1. 細胞培養 28
2.8.2. 支架滅菌與細胞種植 28
2.8.3. 細胞形態 29
2.8.4. 細胞存活率 29
2.9. 統計學分析 29
第三章 實驗結果 30
3.1. 纖維素奈米纖絲 30
3.1.1. SEM和TEM之CNF微觀形態 30
3.1.2. 超音波分散之CNF水分散液 30
3.2. 多方法製備CNFs和PU複合物 30
3.3. 超音波製備之PU/CNF奈米複合物之物性分析 31
3.3.1. 動態光散射分析 31
3.3.2. 熱性能分析 31
3.3.4. 親疏水性分析 32
3.3.5. 機械性能分析 32
3.4. 原位製備之PU/CNF奈米複合物之物性分析 32
3.4.1. 機械性能分析 32
3.4.2. PU/CNF複合墨水（有額外TEA的加入）之製備 33
3.4.3. 動態光散射分析 33
3.4.4. 親疏水性分析 34
3.4.5. 不同CNF改質率 (modification ratio) 對合成配方之影響 34
3.5. 原位製備之PU/CNF複合墨水流變學分析 34
3.5.1. 靜態剪切模式 34
3.5.2. 動態應變掃描模式 35
3.6. PU/CNF複合墨水之微觀形態 35
3.6.1. 穿透電子顯微鏡影像 35
3.6.2. 特殊結構機理猜想 35
3.7. 3D列印複合支架 36
3.7.1.複合支架列印 36
3.7.2. PU/CNF支架清洗 36
3.7.3. PU/CNF支架乾燥 36
3.7.4. PU/CNF和PU/PEO複合合支架列印凍乾 36
3.7.5. 複合支架於液氮脆斷 37
3.7.6. 複合支架掃描電子顯微鏡之影像 37
3.8. 體外降解 37
3.8.1. 支架重量變化 37
3.8.2. 支架尺寸變化 38
3.8.3. 支架壓縮模量變化 38
3.9. 支架組織工程實驗 38
3.9.1. 細胞形態 38
3.9.2. 細胞存活率 39
第四章 討論 40
4.1. 纖維素奈米纖絲 40
4.2. 多方法製備CNFs和PU複合物 40
4.3. 超音波製備之PU/CNF奈米複合物之物性分析 40
4.4. 原位製備之PU/CNF奈米複合物之物性分析 41
4.4.1. 機械性能分析 41
4.4.2. PU/CNF複合墨水（有額外TEA的加入）之製備 41
4.4.3. 動態光散射分析 41
4.4.4. 親疏水性分析 42
4.4.5. 不同CNF改質率 (modification ratio) 對合成配方之影響 42
4.5. 原位製備之PU/CNF複合墨水流變學分析 43
4.6. PU/CNF複合墨水之微觀形態 43
4.7. 3D列印複合支架 44
4.7.1. 複合支架列印 44
4.7.2. PU/CNF支架清洗與乾燥 45
4.7.3. 複合支架於液氮脆斷 45
4.7.4. 複合支架掃描電子顯微鏡之影像 45
4.8. 體外降解 46
4.9. 支架組織工程實驗 46
4.9.1. 細胞形態 46
4.9.2. 細胞存活率 47
第五章 結果 48
參考文獻 49

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