硅溶膠表面改性及環氧樹脂中的應用

材料科學論文編號:CL094  論文字數:11341,頁數:25

目 錄
中文摘要 I
英文摘要 II
目 錄 III
1 緒 論 1
1.1 概述 1
1.2 硅溶膠的基本特性 1
1.2.1 硅溶膠的結構性質 1
1.2.2 硅溶膠的穩定性 2
1.3 表面改性方法和原理 3
1.3.1 表面改性的方法 3
1.3.2 硅烷偶聯劑及其作用機理 3
1.4 納米SiO2在環氧樹脂中的應用 4
1.4.1 環氧樹脂的特性及應用 4
1.4.2 環氧樹脂的增韌 5
2 實驗部分 6
2.1 原料和試劑 6
2.2 實驗步驟 6
2.2.1 異丙醇中分散的納米SiO2的制備 6
2.2.2 偶聯劑的水解 6
2.2.3 納米SiO2表面的改性 6
2.2.4 納米SiO2改性環氧樹脂 6
2.2.5 納米SiO2改性膠粘劑 7
2.3 測試和表征 7
3 結果與討論 8
3.1 納米SiO2在異丙醇中穩定分散的機理分析 8
3.2 偶聯劑改性機理 8
3.3 表面改性的紅外表征 9
3.4 偶聯劑對SiO2粒徑及其分布的影響 10
3.5 偶聯劑對表面接枝量的影響 11
3.6 偶聯劑對SiO2/異丙醇分散體系流變行為的影響 13
3.7 偶聯劑對納米SiO2在環氧樹脂中分散性的影響 14
3.7.1 偶聯劑對納米SiO2在環氧樹脂(固化前)中分散性的影響 14
3.7.2 偶聯劑對納米SiO2在環氧膠粘劑(固化后)中分散性的影響 14
3.8 改性納米SiO2對膠粘劑力學性能的影響 16
4 總結與展望 18
4.1 總結 18
4.2 未來展望 18
致 謝 19
參考文獻 20

摘要：本文研究了自合成偶聯劑(SCA)對硅溶膠中的納米SiO2表面改性，使得原生的親水性SiO2粒子具有一定的親油性，而后將其添加到環氧樹脂中以達到補強增韌的效果。考察了偶聯劑種類與用量對納米SiO2表面改性效果的影響，包括改性后納米SiO2/異丙醇分散體系的流變行為、納米SiO2在有機環氧樹脂體系中分散性以及對環氧樹脂膠粘劑的補強增韌效果。通過紅外光譜(IR)和熱重(TGA)分析證實了納米SiO2表面接枝了一定量的硅烷偶聯劑。粒徑分析(DLS)結果表明改性的SiO2粒子均勻地分散在異丙醇中。將改性SiO2的異丙醇分散液加入到環氧樹脂，通過透射電鏡(TEM)觀察發現分散性良好。考察了納米SiO2對環氧樹脂膠粘劑的拉伸剪切強度和不均勻扯離強度的影響，發現含有偶聯劑處理過的SiO2的膠粘劑樣品的拉伸剪切強度和不均勻扯離強度均比純樹脂要高。

關鍵詞：硅溶膠；環氧樹脂；偶聯劑；表面改性

Abstract： In this study, a series of novel silane coupling agent (SCA) was employed as a modifier for silica particles in the aqueous sol. thus hydrophilic silica particles were converted into hydrophobic ones.The modified silica particles were then added into the epoxy resin, the influences of different SCA and their amount on the surface modification of silica particles was investigated, including the rheological behavior of the silica/isopropanol sol, the dispersion of silica particles in epoxy matrix, and the strengthening and toughening effect of the modified silica particles on epoxy adhesives. The results of Infrared spectrometry (IR) and Thermal Gravity Analysis (TGA) confirmed that a considerable amount of SCA molecules were grafted onto the surface of silica particles. Furthermore, the dispersion of silica particles in isopropanol sol was investigated by Dynamic Lightening Scattering (DLS), showing that a homogenous dispersion was obtained by SCA modification.The modified silica particles were employed as a modifier for the epoxy adhesives. Transmission Electron Microscopy (TEM) was used to observe the dispersion of silica in epoxy adhesives. It shows GPPTES modified silica helped silica particles reached a homogenous dispersion in epoxy resin. Mechanical properties of silica filled epoxy adhesives were studied. Shear strength and uneven tear strength were both increased by addition of treated silica, but deceased by addition of untreated one.

Keywords： colloidal silica；epoxy resin；silane coupling agent；surface modification