硅溶胶表面改性及环氧树脂中的应用

材料科学论文编号:CL094  论文字数:11341,页数:25

目 录
中文摘要 I
英文摘要 II
目 录 III
1 绪 论 1
1.1 概述 1
1.2 硅溶胶的基本特性 1
1.2.1 硅溶胶的结构性质 1
1.2.2 硅溶胶的稳定性 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 硅烷偶联剂及其作用机理 3
1.4 纳米SiO2在环氧树脂中的应用 4
1.4.1 环氧树脂的特性及应用 4
1.4.2 环氧树脂的增韧 5
2 实验部分 6
2.1 原料和试剂 6
2.2 实验步骤 6
2.2.1 异丙醇中分散的纳米SiO2的制备 6
2.2.2 偶联剂的水解 6
2.2.3 纳米SiO2表面的改性 6
2.2.4 纳米SiO2改性环氧树脂 6
2.2.5 纳米SiO2改性胶粘剂 7
2.3 测试和表征 7
3 结果与讨论 8
3.1 纳米SiO2在异丙醇中稳定分散的机理分析 8
3.2 偶联剂改性机理 8
3.3 表面改性的红外表征 9
3.4 偶联剂对SiO2粒径及其分布的影响 10
3.5 偶联剂对表面接枝量的影响 11
3.6 偶联剂对SiO2/异丙醇分散体系流变行为的影响 13
3.7 偶联剂对纳米SiO2在环氧树脂中分散性的影响 14
3.7.1 偶联剂对纳米SiO2在环氧树脂(固化前)中分散性的影响 14
3.7.2 偶联剂对纳米SiO2在环氧胶粘剂(固化后)中分散性的影响 14
3.8 改性纳米SiO2对胶粘剂力学性能的影响 16
4 总结与展望 18
4.1 总结 18
4.2 未来展望 18
致 谢 19
参考文献 20

摘要：本文研究了自合成偶联剂(SCA)对硅溶胶中的纳米SiO2表面改性，使得原生的亲水性SiO2粒子具有一定的亲油性，而后将其添加到环氧树脂中以达到补强增韧的效果。考察了偶联剂种类与用量对纳米SiO2表面改性效果的影响，包括改性后纳米SiO2/异丙醇分散体系的流变行为、纳米SiO2在有机环氧树脂体系中分散性以及对环氧树脂胶粘剂的补强增韧效果。通过红外光谱(IR)和热重(TGA)分析证实了纳米SiO2表面接枝了一定量的硅烷偶联剂。粒径分析(DLS)结果表明改性的SiO2粒子均匀地分散在异丙醇中。将改性SiO2的异丙醇分散液加入到环氧树脂，通过透射电镜(TEM)观察发现分散性良好。考察了纳米SiO2对环氧树脂胶粘剂的拉伸剪切强度和不均匀扯离强度的影响，发现含有偶联剂处理过的SiO2的胶粘剂样品的拉伸剪切强度和不均匀扯离强度均比纯树脂要高。

关键词：硅溶胶；环氧树脂；偶联剂；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