聚氟乙烯高分子的改質與應用之研究: 1. ePTFE之電漿表面改質, 2. 中孔洞二氧化矽的合成與結構之研究, 3. 低介電中孔洞二氧化矽/PTFE之複合高頻基板.

The Modification and Application of PTFE Materials: (1) Plasma Surface Modification of ePTFE, (2) Synthesis and Structure of Mesoporous Silica Materials, (3) Low Dielectric Constant Circuit Boards Based on Mesoporous Silica Filled PTFE Composite Materials.

陳志瑋(Chih-Wei Chen)

指導教授 ： 陳玉惠

中原大學/理學院/化學研究所/博士(2004年)

https://doi.org/10.6840/cycu200400768

摘要

PartⅠ. ePTFE之電漿表面改質
本部分研究，係利用微波電漿反應系統及高週波電漿反應系統在丙烯酸的環境中對ePTFE試片以單一步驟的方式進行表面改質，並使用一系列的表面分析方法如XPS、ATR-FTIR、SEM、AFM、靜態接觸角及威氏平板動態接觸角量測法等評估其改質效果。結果顯示，在功率較高的微波電漿系統中，丙烯酸單體會受到較嚴重的破壞，致使改質層的厚度無法有效提升。高週波丙烯酸電漿系統中改質的成果中則發現，形成之高分子改質層可藉由鍵結或鑲嵌的方式固定於試片表面。改質試片表面之XPS和ATR-FTIR測試結果說明形成之高分子交聯及斷鍵的程度會隨著功率的增加而增加。在動態接觸角的分析中顯示，前進角及後退角分別可下降80˚和50˚之譜，顯示本研究採用之單一步驟高週波丙烯酸電漿改質法有效提昇了ePTFE試片表面的親水性。

Part Ⅱ.中孔洞二氧化矽的合成與結構之研究
本部分研究分別選用陽離子型界面活性劑和非離子型界面活性劑當模板製作中孔洞二氧化矽: MCM-41和SBA-15，並以氮氣吸/脫附量測儀、FTIR和29Si固態-NMR分析孔洞大小及樣品之性質，以SEM及TEM觀察樣品之孔洞型態。其結果顯示，在SBA-15的合成程序中，隨著熟化溫度及熟化時間的不同，可獲得圓球狀、小麥草束狀、橄欖球狀及短棍狀等多種不同型態之中孔洞二氧化矽粒子。為配合第三部份之研究，挑選MCM-41和適當型態且不同孔洞尺寸之SBA-15進行疏水性改質。XRD的結果顯示，改質後之MCM-41和SBA-15皆仍保有其孔洞規則性，而FTIR和29Si固態-NMR的結果則證實，兩者在改質程序後皆成為具有疏水性質之樣品，但MCM-41有較多的疏水性官能基接枝量。

Part Ⅲ. 低介電中孔洞二氧化矽/PTFE之複合高頻基板
此部份之研究，係依據第二部份之研究成果，分別選用MCM-41和數種不同孔洞大小的SBA-15，分別進行表面改質後，以其當填充物，於不同的混合比例下和PTFE乳液進行混掺分別壓製成PTFE/MCM-41-m及PTFE/SBA-15-m複合基板。此基板利用網路分析儀量測其電氣性質，以SEM和EDS觀察試片斷面型態及填充物分佈情形，並分析基板的熱性質、分子組態及表面結構。結果顯示，PTFE/SBA-15-m複合基板之電氣性質(Dk,Df)不佳。而PTFE/MCM-41-m的複合基板系統則顯示，含適當填充物添加量之PTFE/MCM-41-m複合基板，其Z軸熱膨脹係數(CTEz)下降至11.8ppm/℃，可有效提升基板和銅箔貼合後的尺寸穩定性，且其介電常數(Dk)亦降至1.70~2.16間，而消散係數(Df)則仍介於0.0008~0.0049之間，說明此複合基板在高頻領域的應用上具有極大的潛力。

關鍵字

電漿表面改質 ； 鐵氟龍 ； 介電常數 ； 中孔洞二氧化矽 ； 熱膨脹係數 ； 氟系高頻基板

並列摘要

Part Ⅰ. Plasma Surface Modification of ePTFE
In this part, the surface of ePTFE was modified with a one-step process by the Microwave (MW) plasma and Radio frequency (RF) plasma polymerization of acrylic acid, respectively. The modified ePTFE specimens were characterized by a combination of XPS, ATR-FTIR, SEM, AFM, static contact angle and dynamic contact angle (Wilhelmy plate method) measurements to evaluate the efficiency of the modification. It was found that in the MW plasma system, the acrylic acid monomer was seriously cleaved due to the higher input power. Therefore, it was unable to efficiently form the polymer layer depositing on the ePTFE surface. On the other hand, in the RF plasma system, the acrylic acid polymer was successfully formed, grafting on the sample surface and/or anchoring in the pores of the ePTFE matrix. The results of XPS and ATR-FTIR measurements revealed that the extent of cross-linking and bond scission of the plasma deposition increased with the power applied. The results of AFM and SEM showed a distinct change in the morphology and roughness of the surface after the modification. Compared with the pristine eFTFE the advancing contact angle (θa) and the receding contact angle (θr) were decreased by about 80° and 50°, respectively, exhibiting a large improvement in the surface hydrophilicity for the modified ePTFE specimens.

Part Ⅱ. Synthesis and Structure of Mesoporous Silica Materials
In this part, we used a cationic surfactant and a nonionic surfactant as the template to synthesize the mesoporous silica MCM-41 and SBA-15, respectively. The properties of the mesoporous materials were investigated by N2 adsorption/desorption isotherms, FTIR, 29Si solid state-NMR, SEM and AFM. The results of the investigation revealed that with different aging temperature and aging time, various kinds of morphology such as sphere-like, wheat-like, football-like and road-like were obtained. In order to hybrid with ePTFE emulsion for the study in Part Ⅲ, the as-prepared MCM-41 and the SBA-15 with suitable morphology and different pore size were selected and further modified hydrophobically by the silylation. The results of XRD measurements revealed that the long range order of the as-prepared MCM-41 and the SBA-15 was retained after the silylation. The FTIR and 29Si solid state-NMR spectra indicated that the silylation reaction successfully made the hydrophilic MCM-41 and the SBA-15 samples hydrophobic products. Besides, it also showed that compared with the modified SBA-15 (SBA-15-m) the modified MCM-41 (MCM-41-m) contained more hydrophobic functional groups, revealing a better hydrophobicity.

Part Ⅲ. Low Dielectric Constant Circuit Boards Based on Mesoporous Silica Filled PTFE Composite Materials
In this part, the hydrophobically modified mesoporous silica powders, MCM-41-m and three kinds of SBA-15 with different pore size prepared in Part Ⅱ, were used as the fillers to hybrid with a various amount of PTFE emulsion to prepare a series of the PTFE/mesoporous silica nanocomposite materials. The composite materials were then compressed to form the corresponding rigid boards. The properties of the boards were investigated by a combination of Network Analyzer, DSC, TGA, TMA, XPS and 29Si solid state-NMR measurements. It was found that the PTFE/SBA-15-m composite boards possessed of higher water absorption as well as dielectric constant and dissipation factor. However, in the PTFE/MCM-41-m system, it was found that with proper amount of MCM-41-m the z-axis coefficient of thermal expansion (CTEz) was lowered to 11.8ppm/℃, which was very close to that of copper foil, revealing a large improvement in the mount ability with copper foil. The dielectric constants and the dissipation factors were ranging between 1.70 to 2.16 and 0.0008 to 0.0049, respectively. The results indicated that the as-prepared PTFE/MCM-41-m composite materials are potentially useful as RF/Microwave substrate materials.

並列關鍵字

Coefficient of thermal expansion ； Dielectric constant ； ePTFE ； Mesoporous materials ； PTFE composite board ； Plasma surface modification

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