多壁碳纳米管改性环氧树脂胶黏剂实验研究
Experimental study on epoxy resin adhesive modified by multi - walled carbon nanotubes
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摘要: 将一种环氧树脂和表面羟基化的多壁碳纳米管(MWCNTs)按照质量比100∶0.1进行配比, 以超声波分散法制备MWCNTs/环氧树脂胶黏剂, 考察了两种硅烷偶联剂KH550和KH560对MWCNTs改性效果的影响。采用FTIR、 DSC、 DMA、 流变仪研究了MWCNTs对胶黏剂固化行为和流变特性的影响, 并结合断口形貌观察, 测试分析了MWCNTs对胶黏剂拉伸剪切强度和冲击强度的影响。结果表明: 硅烷偶联剂能与MWCNTs表面的羟基发生缩合反应, 增强了MWCNTs与环氧树脂基体的亲和性, 从而影响胶黏剂固化反应及黏度-剪切速率曲线; 经KH550改性的MWCNTs明显提高了胶黏剂与金属的界面粘结性, Al-Al拉伸剪切强度较无MWCNTs的胶黏剂提高了46.4%; 添加MWCNTs使胶黏剂的冲击断面更为粗糙, 开裂面积更大; 添加MWCNTs+KH550的胶黏剂冲击强度提高了44.1%, 说明MWCNTs/环氧树脂间界面性能对发挥MWCNTs的增韧效果非常重要。Abstract: A multi-walled carbon nanotubes (MWCNTs)/epoxy resin adhesive was prepared with the EP resin and surface hydroxylating MWCNTs by a mass ratio of 100∶0.1 using ultrasonic dispersion method. The effects of two kinds of silane couple agents KH550 and KH560 on the modified degree of the MWCNTs were investigated. The effects of the MWCNTs on curing behavior and rheological property of the adhesives were studied by means of FTIR, DSC, DMA and rheometer. Based on the observation of fracture cross-section, the influences of MWCNTs on the shear strength by tension loading and impact strength were analyzed. The experimental results show that the silane couple agents have the condensation reaction with-OH on the surface of MWCNTs, and can improve the compatibility between MWCNTs and epoxy resin. Thus, the silane couple agents influence the curing reaction and viscosity-shear rate curves of the adhesives. The MWCNTs modified by KH550 can obviously improve the bond property between the adhesives and metal, and the Al-Al shear strengths by tension loading are raised by 46.4% compared with the one without MWCNTs. The impact fracture cross-sections of the adhesives with MWCNTs are much rougher and have larger areas of crack. In addition, the impact strength of the adhesive with MWCNTs+KH550 is raised by 44.1% compared with the one without MWCNTs, indicating that the interphase property between MWCNTs and epoxy resin is very important for the toughening effect of the MWCNTs.