高性能聚醯亞胺及其混成材料之合成與應用

Synthesis and Applications of High Performance Polyimides and Their Hybrid Materials

李孟憲(Meng-Hsien Li)

指導教授 ： 陳文章

國立臺灣大學/工學院/化學工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.01374

摘要

聚醯亞胺為一具有高功能的高分子，因具有良好的熱穩定性、抗化性和高機械強度而被廣泛運用在各個產業之中。聚醯亞胺/無機混成材料已經被普遍地用於提升熱性質、光學性質和機械性質。然而，開發具有高光學穿透性、高熱穩定性、極佳的機械強度和感光圖案化之多功能聚醯亞胺/二氧化矽混成材料仍具有挑戰性。除此之外，混摻電活性基團於聚醯亞胺並應用於光電元件上之研究仍未被探討。因此，本論文首先探討具有高熱/機械性質之感光型聚醯亞胺/二氧化矽薄膜之製備。接著，透過摻入具共軛結構之小分子，製備出可以作為有機場效應記憶體元件中載子儲存層的聚醯亞胺類超分子，茲敘述如下：
本研究第二章，首先合成出具有高透明性、高機械性質和高耐熱性的聚醯亞胺混成材料光學膜。聚醯亞胺的合成是利用具有羥基(hydroxyl)和三氟甲基的芳香族雙胺 (2,2’-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 6FOH)與柔軟具有氧原子的芳香族雙酸酐 (4,4’-oxydiphthalic anhydride, ODPA)。接續加入四甲氧基矽烷 (Tetramethyl orthosilicate, TMOS) 進行凝膠反應與高溫熱閉環程序製備出具有不同二氧化矽含量的聚醯亞胺混成材料薄膜。延續聚醯亞胺薄膜良好的光學、機械及熱性質，藉由導入末端具雙鍵結構的無機矽烷基團(3-(trimethoxysilyl) propyl methacrylate, MPTMS) 和光起始劑 Irgacure-819 能成功製作出具有負型光阻圖案的感光型混成材料聚醯亞胺薄膜。本章節研究結果顯示，我們可以藉由添加的二氧化矽含量提升聚醯亞胺之熱穩定性和機械強度。聚醯亞胺混成薄膜可以達到高的熱穩定性(熱膨脹係數(CTE)可以低於17.92 ppm/oC)、良好的光學穿透度 (在410nm下大於85%，膜厚大於20 μm) 和超乎預期的機械性質 (tensile Strength = 93.07 MPa, tensile Modulus = 4.28 GPa 和 elongation = 2.99 %)。除此之外，我們可以獲得在厚度7μm下具有50μm之清晰解析度之負型光阻圖案。
本研究第三章，研究目標針對基於p型並五苯的非揮發性場效電晶體式記憶體元件，以已合成出之聚醯亞胺高分子 [PI(6FOH-ODPA)] 混摻具有捕捉電洞特性之共軛結構小分子1-氨基芘作為儲存載子的高分子駐極體層。利用聚合物側鏈上的羥基透過氫鍵作用力鍵結添加的1-氨基芘小分子並使其均勻分散形成超分子材料。混摻物在電晶體式記憶體元件中具有明顯的電洞儲存性，所製備出之元件主動層載子電洞遷移率約在10-1 cm2V-1s-1。在 ± 30 V寫入抹除操作下，記憶體視窗操作範圍可達20.56 V，高低導電態的電流比約為103~104，元件還具有高電荷續航時間約104秒，且性能上可重複讀寫可逆操作達100次。這顯示所製備的元件具有應用於非揮發性記憶體的潛力。聚醯亞胺/1-氨基芘間的電荷轉移現象與記憶體元件特性間的關聯也有做深入的探討。
本研究顯示出藉由導入無機、感光或電活性基團修飾過的聚醯亞胺材料具有應用於不同光電領域的潛力。

關鍵字

聚醯亞胺混成材料 ； 感光型聚醯亞胺 ； 場效電晶體式記憶體元件 ； 1-氨基芘

並列摘要

Polyimides (PI) are high performance and functional polymers widely used in the fields of optoelectronics and semiconductor fabrications due to their good thermal stability, chemical resistance and outstanding mechanical strengths. Polyimide/inorganic hybrid materials have been commonly used to enhance the physical properties, such as thermal, mechanical, and optical properties. However, the development of polyimide/silica hybrid films with the multi-functionality of high optical transmittance, superior thermal stability, excellent mechanical strength, and photo-patternable remains challenges. In addition, the incorporation of electroactive moiety into polyimides for electrical device applications has not been fully explored yet. In this thesis, we firstly explored the preparation of photosensitive PI/silica hybrid films with high thermal/mechanical properties. Sequentially, through blending with small conjugated molecules, the developed polyimide-based supramolecules could be used in organic field effect transistor memory devices as a charge storage layer. The detailed results and discussion are described as following：
In Chapter 2, we synthesized the polyimide/silica hybrid optical films with high optical transmittances, high mechanical strength and high thermal stability. The polyimides were prepared using the monomers of soft aromatic dianhydride, 4,4’-oxydiphthalic anhydride (ODPA) with ether group and diamine, 2,2’-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FOH) with hydroxyl and hexafluoroisopropylidene group, then followed with tetramethyl orthosilicate, (TMOS) for sol-gel reaction, and followed by the thermal imidization to obtain polyimide/silica hybrid optical films with different silica content. To explore the photosensitive application of polyimide, we introduced 3-(trimethoxysilyl) propyl methacrylate (MPTMS) with vinyl group and photo-initiator Irgacure-819 to prepare negative-type photoresist patterns. The experimental results showed that the thermal-resistance and mechanical strength of the hybrid materials as increasing the silica content. In addition, the hybrid films achieved high thermal stability (the coefficient of thermal expansion (CTE) could be as low as 17.92 ppm/oC), good optical transparency (>85 % at 410 nm, thickness >20 μm), and exceptional mechanical properties (tensile Strength = 93.07 MPa, tensile Modulus = 4.28 GPa and elongation = 2.99 %). Additionally, a clear negative-tone image with resolution 50 μm in 7 μm thickness film could be obtained.
In Chapter 3, the nonvolatile memory characteristics of p-type pentacene-based organic field-effect transistor (OFET) using the synthesized polymer electrets PI(6FOH-ODPA) and its supremolecules were systematically studied. The supramolecular materials were prepared by hydrogen-bonding 1-aminopyrene with the hydroxyl functional group of the PI(6FOH-ODPA). The effect of the 1-aminopyrene composition on the hole-trapping capability of the PI(6FOH-ODPA) electret was investigated. Under the operating voltage in ± 30 V, the prepared devices exhibited a memory window of 20.56 V and hole-mobility of up to 10-1 cm2V-1s-1. Furthermore, the devices showed a long charge-retention time for 104 s with the ON/OFF current ratio of around 103~104 and multiple switching stability over 100 cycles. This reveals that the device has potential applications in nonvolatile memory devices. The relationship between the charge transfer effect of polyimide/1-aminopyrene and their memory characteristics was also discussed.
This thesis demonstrated that the polyimides modified with the inorganic, photosensitive or electroactive moieties could be potentially used in different electrical/photonic applications.

並列關鍵字

polyimide hybrid materials ； photosensitive polyimide ； OFET memory device ； 1-aminopyrene

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