Experimental study on epoxy resin adhesive modified by multi-walled carbon nanotubes

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 viscosityshear rate curves of the adhesives. The MWCNTs modified by KH550 can obviously improve the bond property between the adhesives and metal, and the AlAl 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.