不同孔隙之疏水性二氧化矽之製備、鑑定及其所衍生之聚亞醯胺複合材在高頻低介電材料之比較研究

本碩士論文之研究目標為製備同時具有介電常數及低介電損失的聚亞醯胺/疏水介孔二氧化矽複合薄膜。材料的基本設計概念為先合成具疏水性的無機介孔二氧化矽粉體，然後將其導入聚亞醯胺中進行熱縮合的高分子聚合反應，期待利用導入甲基(-CH3)的疏水特性於二氧化矽粉體降低吸水率(水的介電常數~ 80)，及利用二氧化矽粉體的介孔特性導入空氣(空氣的介電常數~ 1)，希望藉由增強二氧化矽粉體疏水及介孔特性降低所衍生的聚亞醯胺薄膜的介電性質，並研究其在低頻及高頻狀態下的介電行為。　　在合成無孔二氧化矽粉體的部分，首先利用鹼催化的溶膠凝膠法進行四乙氧、3-氨基丙基三乙氧基矽烷及甲基三甲氧基矽烷進行共水解/縮合反應，以合成同時具胺基修飾及甲基修飾之二氧化矽粉體(AMS)。所合成之二氧化矽粉體利用固態核磁共振(SS NMR)、紅外線光譜儀(FT-IR)進行化學結構的鑑定；利用水滴接觸角與熱失重分析儀(TGA)對二氧化矽粉體進行親疏水性質的探討。　　在合成介孔二氧化矽粉體的部分，首先由不同官能基比例之無孔二氧化矽中挑選最佳比例。接著在以抗壞血酸及果糖做為非介面活性劑模板的存在下，以鹼催化溶膠凝膠法進行四乙氧、3-氨基丙基三乙氧基矽烷及甲基三甲氧基矽烷的共水解/縮合反應，以合成同時具胺基修飾及甲基修飾的介洞二氧化矽粉體(標示為AMS1A & AMS1F)，接著以大量清水進行模板沖洗。所合成的無孔二氧化矽粉體及介孔二氧化矽粉體的鑑定是利用固態核磁共振光譜儀(SS NMR)、紅外線光譜儀(FT-IR)進行化學結構的鑑定；以氮氣吸脫附儀(BET)進行介孔二氧化矽粉體的孔洞大小及表面積大小的檢測；以穿透式電子顯微鏡(TEM)進行二氧化矽粉體表面型態的探討。　接著進一步將無孔及有孔二氧化矽粉體添加進入二胺(ODA)與二酸酐(BPDA)的反應中，進行熱亞醯胺化反應以合成一系列聚亞醯胺/疏水介孔二氧化矽複合薄膜。以銅蝕刻方法進行塗布，並利用全反射紅外線光譜儀(ATR-IR)進行結構鑑定；並以精密阻抗分析儀器進行低頻介電性質探討，且以及10 GHz共振腔器進行高頻介電性質探討；並利用熱失重分析儀(TGA)與熱導係數儀(Hot Disk, HD)進行熱性質探討；並以動態機械分析儀(DMA)進行機械性質探討。　　比較添加不同官能基比例、不同表面積、不同孔洞大小二氧化矽之聚亞醯胺複合薄膜材料，可歸納出以下的結論： (1) 添加較為疏水(亦即具有甲基)之介孔二氧化矽粉體於聚亞醯胺薄膜中，可有效降低聚亞醯胺薄膜之介電常數及介電損失之趨勢。 (2) 添加表面積較高之疏水介孔二氧化矽(以抗壞血酸為模板)粉體於聚亞醯胺薄膜中，其介電常數及介電損失相對下降較多。

關鍵字

聚亞醯胺；二氧化矽；介電特性；高頻介電

並列摘要

The research goal of this master's thesis is to prepare a polyimide/hydrophobic mesoporous silica composite film with both low dielectric constant and low dielectric loss. The basic design concept of the material is to first synthesize a hydrophobic inorganic mesoporous silica powder, and then introduce it into a polyimide by thermal condensation polymerization. It expected to reduce the dielectric constant and dielectric loss by utilizing the hydrophobicity through introducing methyl group on the surface of silica powder to reduce water absorption (dielectric constant of water ~ 80). Furthermore, air (dielectric constant of air ~ 1) was been introduced into the mesopores of silica powder. The hydrophobic and mesoporous properties of the silica powder reduce the dielectric properties of the polyimide film derived from the film and study its dielectric behavior at low and high frequencies. In the synthesis of non-porous silica powder, the co-hydrolysis/ condensation reaction of tetraethyl orthosilicate, (3-aminopropyl)- triethoxysilane and methyltrimethoxysilane is first carried out by a base-catalyzed sol-gel method. The synthesis of silica powder (AMS) with both primary amine and methyl group is been carried out. The synthesized silica powder was identified by solid-state nuclear magnetic resonance (SS-NMR) and Fourier-information infrared (FT-IR) spectroscopy。 Hydrophobic characteristic of silica powder was demonstrated by the measurement of water droplet contact angle and thermal weight loss analyzer (TGA), respectively. In the fraction of mesoporous silica powder, the optimum ratio was selected from non-porous silicas having different functional ratios. Subsequent co-hydrolysis of tetraethyl orthosilicate, (3-aminopropyl)- triethoxysilane and methyltrimethoxysilane by base-catalyzed sol-gel method in the presence of ascorbic acid and fructose as a template for non-surfactant templates. The condensation reaction was carried out to synthesize a mesoporous silica powder (labeled as AMS1A & AMS1F) having both an amine group modification and a methyl group modification, followed by template flushing with a large amount of water. The synthesized non-porous silica powder and mesoporous silica powder was identified by SS-NMR spectrometry and FT-IR for chemical structure identification. Pore size and surface area of mesoporous silica powder was been examined by BET. The surface morphology of silica powder was been investigated by a transmission electron microscope (TEM). Then, the non-porous and porous silica powder has further added into the reaction of diamine (ODA) and dianhydride (BPDA), and the thermal imidization reaction is been carried out to synthesize a series of polyimide/hydrophobic mesopores silica composite films. Coating by copper etching method, and structural identification of composite films by total reflection infrared spectroscopy (ATR-IR); low-frequency dielectric properties were investigated by precision impedance analysis instrument, and high-frequency dielectric properties were discussed by 10 GHz resonator; the thermal properties of the thermogravimetric analyzer (TGA) and the thermal conductivity meter (Hot Disk, HD) were investigated. Mechanical property of composite films had discussed by dynamic mechanical analyzer (DMA). Comparing the polyimide composite films with different functional group ratios, different surface areas and different pore sizes of silica, the following conclusions summarized as follows: (1) Adding a relatively hydrophobic mesoporous silica powder to a polyimide film can effectively reduce the dielectric constant and dielectric loss of the polyimide film. (2) The addition of hydrophobic mesoporous silica oxide (ascorbic acid as a template) with a higher surface area has a large decrease in dielectric constant and dielectric loss of the polyimide film.