環氧樹脂添加不同孔洞特性之疏水性二氧化矽的製備、鑑定及其複合材料在高頻低介電上之應用研究

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環氧樹脂/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，然後將其導入環氧樹脂中進行高分子開環聚合反應，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環氧樹脂薄膜的介電性質，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將四乙氧基矽烷、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。接著在以果糖及葡萄糖做為非介面活性劑模板的情況下，以鹼催化溶膠凝膠法進行四乙氧基矽烷、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，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)對二氧化矽粉體進行內部型態的探討。接著進一步將無孔及有孔二氧化矽粉體添加進入胺類硬化劑(T-403)與雙酚A型環氧樹脂(DGEBA)的反應中，進行熱硬化開環聚合反應，以合成一系列環氧樹脂/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)進行熱性質探討；以及動態機械分析儀(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環氧樹脂複合薄膜材料，可歸納出以下的結論： (1) 添加較為疏水之介孔二氧化矽粉體於環氧樹脂薄膜中可有效降低環氧樹脂薄膜之介電常數及介電損失。 (2) 添加表面積較高之疏水介孔二氧化矽粉體於環氧樹脂薄膜中，其介電常數及介電損失下降較多。

關鍵字

環氧樹脂；二氧化矽；介電

並列摘要

The research goal of this master's thesis was to prepare an epoxy resin/ hydrophobic mesoporous silica composite film with both dielectric constant and low dielectric loss. The basic experimental design concept of the material was to first synthesize a hydrophobic inorganic mesoporous silica powder, and then introduce it into an epoxy resin for thermal epoxide ring-opening polymerization. Introduction of hydrophobic methyl (-CH3) to silica powder resulted to its decreased dielectric constant and dielectric loss, thereby reducing its water absorption (dielectric constant of water ~ 80). Furthermore, air was introduced into the mesopores of silica powder (dielectric constant of air ~ 1). The hydrophobic and mesoporous properties of the silica powder consequently reduced the dielectric properties of the epoxy resin film and its dielectric behavior at low and high frequency were then studied. For synthesis of non-porous ceria powder, the co-hydrolysis/ condensation reaction of tetraethyl orthosilicate, (3-aminopropyl)- triethoxysilane and methyltrimethoxysilane was first carried out by a base-catalyzed sol-gel method. Silica powder (AMS) modified with both amine and methyl groups was synthesized. The chemical structure of the modified silica powder was confirmed by solid state nuclear magnetic resonance (SS NMR) and Fourier-Transformation infrared spectroscopy (FT-IR); hydrophobicity of the silica powder was investigated using a water droplet contact angle and a thermal weight loss analyzer (TGA). For the mesoporous silica powder, the optimum ratio was first selected from non-porous silicas having different functional ratios. Subsequent co-hydrolysis of tetraethyl orthosilicate, (3-aminopropyl)triethoxysilane and methyltrimethoxysilane with a base-catalyzed sol-gel method, in the presence of fructose and glucose as a non-surfactant template, was performed. The condensation reaction was carried out to synthesize a mesoporous silica powder functionalized to have both amine and methyl groups, followed by template flushing with a large amount of fresh water. The synthesized non-porous silica powder and mesoporous silica powder were identified by SS NMR and FT-IR for chemical structure characterization; pore size and surface area of the mesoporous silica powder were examined by BET; and the surface morphology of silica powder was investigated by a transmission electron microscope (TEM). After which, the non-porous and porous silica powder were further added into the reaction of the amine hardener (T-403) and the bisphenol A epoxy resin (DGEBA), and the thermosetting ring-opening polymerization reaction was carried out to synthesize a series of epoxy resin/hydrophobic mesoporous silica composite films. Copper etching was used to as a coating method, and structural identification of the fabricated composite films was done by attenuated total reflection infrared spectrometer (ATR-IR); low-frequency dielectric properties of films were investigated by precision impedance analysis instrument; and high-frequency dielectric properties of films were evaluated by 10 GHz resonator. In addition, thermal and mechanical properties of the films were investigate using thermogravimetric analyzer (TGA) and dynamic mechanical analyzer (DMA), respectively. Comparing the properties of the synthesized epoxy resin composite film materials with different functional group ratios, different surface areas and different pore sizes of silica, the following conclusions were drawn: (1) The addition of a relatively hydrophobic mesoporous silica powder to an epoxy resin film effectively reduced the dielectric constant and dielectric loss of the epoxy resin film. (2) The addition of a hydrophobic mesoporous silica powder having a relatively high surface area to an epoxy resin film resulted to a large decrease in dielectric constant and dielectric loss.