摘要实现有机硅与环氧的化学连接并制备综合性能优异的复合涂层一直是人们研究的热点和市场的需求，本文以二官能度的异氰酸酯作为媒介合成了不同分子链长度有机硅改性环氧涂层，主要进行了以下几个方面的研究：探索了MDI与PDMS及环氧E-51反应反应活性的快慢，制备出了MDI/PDMS预聚体并用其改性小分子量的环氧树脂。将初步改性产物与大分子量的环氧混合制备了不同预聚物含量的复合涂层。86499
FTIR测试表明制备的-NCO封端的PDMS预聚体为预期产物。交流阻抗和盐雾测试的结果表明改性涂层的耐蚀性远远优于未改性涂层。同一链长度的PDMS改性涂层的阻抗值随着预聚体含量的增加而增加，具有长分子链PDMS的改性产物的阻抗值略大于短链PDMS改性涂层的阻抗值。盐雾实验的结果也有相同趋势。SEM对复合涂层的微观形貌分析揭示了不同含量和不同分子链长度的聚二甲基硅氧烷在环氧基体中的分散状态不同。随着PDMS含量的增加以及聚二甲基硅氧烷分子链长度的增加，其在环氧母体中的分散尺度增大，其相分离行为越明显。相比于MDI固化的环氧树脂，改性涂层水接触角值增大。随着PDMS含量的增加，改性环氧涂层的接触角值递增，其表面能降低。长链PDMS改性的环氧涂层接触角值略大于短链PDMS改性涂层的接触角。
毕业论文关键词：链长；有机硅；改性；环氧；相分离
Abstract Achieving chemical link between silicone and epoxy resin and preparing a composite coating with excellent comprehensive properties is always being the research hotspot and the requirement of market。 This thesis uses MDI as medium for synthesis of modified epoxy resin coating with different chain-length silicone。 Researches are as follows: The reaction activity of MDI /PDMS and MDI/E-51 were explored。 -NCO terminated prepolymer was successfully prepared by mixed the MDI with PDMS and was confirmed by FTIR。 The epoxy resin which has low molecular weight was modified with the prepolymer and the composite coating was obtained by mixed the modifier with E-44。
The results of EIS and CASS suggest that the corrosion resistance of modified coating is superior to the unmodified coating。 The impedance value of the modified coating with same chain-length PDMS increases with the increasing prepolymer concentration, the impedance value of the modified coating with long chain-length PDMS slightly higher than that with short chain-length PDMS。 The result of CASS has the same trend。 SEM shows that the dispersed state of PDMS in composite coating is different with PDMS concentration and the PDMS’s length of chain。 With the increasing of PDMS concentration and the increasing of PDMS’s length, dispersed scale of PDMS in epoxy becomes larger and behavior of its phase separation becomes more obvious。 Compared to the MDI cured epoxy, the water contact angle of modified coating is higher。 The contact angles of the modified coating increase with the increasing of PDMS concentration。 The contact angles of the modified coating with long chain-length PDMS higher than that with short chain-length PDMS。
Keywords: chain-length; silicone; modify; epoxy resin; phase separation
目 录
第一章 绪论 1
1。1 前言 1
1。2 环氧树脂概述 1
1。2。1 环氧树脂 1
1。2。1 环氧树脂的特点 2
1。3 环氧树脂的改性现状 2
1。4 有机硅改性环氧树脂研究现状 5
1。4。1 有机硅共混改性环氧 不同链长聚二甲基硅氧烷改性对环氧涂层性能的影响:http://www.youerw.com/cailiao/lunwen_106835.html