積層製造 (Additive Manufacturing, AM) 又稱3D列印 (Three Dimensional Printing, 3DP)，具有可輕鬆製造出複雜形狀物件，以及大幅減少材料浪費的特點，使其在近十幾年來快速的發展，並且基於製造時間及成本考量，已逐漸在一些領域上取代了傳統製造技術。而光固化 (Vat Photopolymerization, VP) 技術因具有速度快、精度高、表面品質良好等優勢而在3DP中備受矚目，然而其受到光敏樹脂材料性質普遍不佳的限制，因而無法被廣泛的在工程應用中被使用。而隨著智能材料出現，結合3DP誕生出了4D列印，其可通過施加外部刺激，而隨時間以受控方式產生變化，然而目前仍然缺乏具備良好機械強度的智能材料，可應用層面較少。
本研究以開發具有高強度、高韌性及形狀記憶功能，且可用於市售常見光固化列印機之光敏樹脂材料為目的，期望可以改善光固化技術在材料上的限制，並進一步拓展其應用領域。因此本研究以聚氨酯丙烯酸酯 (Polyurethane Acrylate, PUA) 寡聚物，及三羥甲基丙烷三丙烯酸酯 (Trimethylolpropane triacrylate, TMPTA) 稀釋單體，與TPO光起始劑及熱自由基起始劑混合。並添加了Bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate光穩定劑，最終製備出一款使用光/熱雙固化系統增強性能之Tough-H樹脂。
實驗結果顯示，Tough-H樹脂配方在室溫下黏度約603.5 cP，較多數市售高強韌樹脂更低，且適用於下照式光固化列印機。由DSC及TMA測試玻璃轉化溫度(Tg)結果分別約為55.1°C及51.6°C。浸泡水中24小時的吸水率僅約0.92%。機械性質方面，邵氏硬度達到84 HD，拉伸強度及拉伸模量高達57.8 MPa及2481.7 MPa，同時有斷裂伸長率10.7%及耐衝擊強度19.37 J/m的良好韌性。形狀記憶測試結果表示，形狀固定率及形狀恢復率皆有達到90%以上。總結以上結果，並與市售高強韌樹脂相比，本研究成功地開發出了具低黏度、低收縮率、低吸水率、高強度、良好韌性及形狀記憶功能的光敏樹脂材料，並且已經探討了該樹脂材料在輕量化晶格結構的適用性。

Additive manufacturing (AM), also known as three dimensional printing (3DP), is characterized by its ability to easily produce complex-shaped objects and significantly reduce material waste, leading to its rapid development in recent years. Furthermore, considering manufacturing time and costs, it has gradually replaced traditional manufacturing technologies in some fields. Among many AM technologies, vat photopolymerization (VP) technologies have gained significant attention due to its advantages of high speed, superior resolution, and excellent surface quality. However, it is limited by the subpar properties of the photosensitive resin materials, hindering its widespread use in engineering applications. And with the emergence of smart materials, the combination of additive manufacturing technologies has given rise to 4D printing. It can undergo changes over time by applying external stimuli such as light, electricity, or temperature. However, there is still a lack of smart materials with superior mechanical strength.
This study aimed to develop photosensitive resin with high strength, toughness, and shape memory ability for use in commercially available VP printers, with the expectation of further expanding the application scope of VP technologies. Therefore, this study utilized polyurethane acrylate (PUA) as the oligomer and trimethylolpropane triacrylate (TMPTA) as the monomer, mixed with diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) as the photo-initiator and thermal radical initiators, and incorporated Bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate as the stabilizer. Finally, a Tough-H resin with enhanced material properties using photo-thermal dual curing system has been developed.
The experimental results indicated that the viscosity of Tough-H resin at room temperature is approximately 603.5cP, which is lower than many commercially available high strength and tough resins. It is suitable for use in bottom-up VP printers. The glass transition temperature (Tg) obtained from DSC and TMA testing are approximately 55.1°C and 51.6°C, respectively. The water absorption rate after 24 hours of immersion in water is only approximately 0.92%. As for the mechanical properties, the Shore hardness reaches 84 HD, tensile strength and elastic modulus reaching 57.8 MPa and 2481.7 MPa, respectively. Furthermore, it exhibited good fracture toughness at 10.7% and an impact strength of 19.37 J/m. In shape memory testing, the shape fixing ratio and shape recovery ratio have both exceeded 90%. In summary, compared to commercially available resins, this study has successfully developed a photosensitive resin with low viscosity, low shrinkage, low water absorption, high strength, good toughness, and excellent shape memory functionality. And the applicability of this resin material in lightweight lattice structures has also been explored.

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