超声强化氨基化多壁碳纳米管改性环氧黏接接头性能研究

Effect of Ultrasonic Treatment on Properties of MWCNTs-NH_(2)Reinforced Epoxy Bonded Joints

目的探究超声处理对氨基化多壁碳纳米管(MWCNTs-NH_(2))改性环氧黏接接头黏接性能和热稳定性的影响,为强化MWCNTs-NH_(2)改性环氧胶黏剂与铝合金的黏接提供参考。方法通过机械搅拌与声波破碎的方法将质量分数为0.75%的MWCNTs-NH_(2)添加到环氧胶黏剂基体中,使用MWCNTs-NH_(2)改性环氧胶黏剂制备铝合金黏接接头,基于超声辅助黏接工艺在铝合金黏接过程中进行超声处理。通过傅里叶变换红外光谱仪(FTIR)分析MWCNTs-NH_(2)改性环氧胶黏剂基体官能团的变化情况。采用单搭接剪切强度试验测定黏接接头的拉伸剪切强度。通过扫描电子显微镜(Scanning Electron Microscope,SEM)观察黏接接头拉伸失效断面以及铝合金与胶黏剂间的黏接界面。通过热失重分析仪(TGA)测试并记录胶黏剂试样质量随温度变化的曲线。结果经超声处理后,MWCNTs-NH_(2)与树脂基体间的化学反应增强。与纯环氧黏接接头相比,超声处理后的MWCNTs-NH_(2)改性环氧黏接接头拉伸剪切强度提高了49.2%,黏接接头断面上的内聚失效部分显著增加。微观上,超声处理后的MWCNTs-NH_(2)改性环氧黏接接头断面显示出更加复杂的塑性变形,胶黏剂与铝合金表面结合得更加紧密,MWCNTs-NH_(2)随环氧胶黏剂流入铝合金表面凹槽内。经超声处理后,胶黏剂在失重率为5%、10%、50%以及热失重速率最大时的特征温度上升。结论超声处理改善了MWCNTs-NH_(2)与树脂基体的界面结合性能,促进了MWCNTs-NH_(2)改性环氧胶黏剂在铝合金表面的渗透和填充情况,形成了MWCNTs-NH_(2)对铝合金和胶黏剂的桥接。超声处理提高了改性环氧胶黏剂的交联密度,改善了胶黏剂的热稳定性。

The work aims to explore the effect of the ultrasonic treatment on the bonding property and the thermal stability of MWCNTs-NH_(2)reinforced epoxy bonded joints,so as to provide reference for improving the bonding between the adhesive and aluminum alloy.The MWCNTs-NH_(2)with a mass fraction of 0.75wt%was added to the epoxy adhesive substrate by mechanical stirring and sonication and applied to bond the aluminum alloy joints.Based on the ultrasonic assisted bonding process,the aluminum alloy joints were bonded with the application of the ultrasonic treatment.The changes in functional groups of the epoxy adhesive substrate were analyzed with a Fourier transform infrared spectroscopy(FTIR).Single lap shear tests were applied to test the single lap shear strength of the bonded joints.A SEM was used to observe the tensile failure fracture surface of the adhesive joints,and the bonding interface between aluminum alloy and adhesive.The curve of the continuous change of adhesive samples mass with temperature was tested and recorded with a thermogravimetric analyzer(TGA).The chemical reaction between MWCNTs-NH_(2)and epoxy resin was enhanced with the ultrasonic treatment.Compared with the neat epoxy bonded joints,the tensile shear strength of the MWCNTs-NH_(2)reinforced epoxy bonded joints with the ultrasonic treatment increased by 49.2%,and the cohesive failure area on the tensile failure fracture surface increased significantly.Microscopically,the fracture surface of MWCNTs-NH_(2)reinforced epoxy bonded joints with the ultrasonic treatment showed more complex plastic deformation,and the adhesive was more compact with the surface of aluminum alloy.MWCNTs-NH_(2)flowed into the groove of aluminum alloy surface with epoxy adhesive.The characteristic temperature of MWCNTs-NH_(2)reinforced epoxy adhesive at 5%,10%,50%weight loss rate and the maximum thermal weight loss rate increased.The results show that the ultrasonic treatment improves the interface bonding properties between MWCNTs-NH_(2)and resin substrate,promotes the penetration and filling of MWCNTs-NH_(2)reinforced epoxy adhesive on the surface of aluminum alloy,and forms the bridge between aluminum alloy and adhesive by MWCNTs-NH_(2).The crosslinking density of MWCNTs-NH_(2)reinforced epoxy adhesive is increased and the thermal stability is improved with the ultrasonic treatment.