Effect of carbon nanotube enhanced adhesives on degradation of bonded joints in corrosive environments

Abstract

The aim of this work is to study the lap shear strength as well as the response to galvanic corrosion and environmental degradation of Multi Wall Carbon Nanotube (MWCNT) enhanced adhesive bonding on metallic substrates so as to establish whether the response of MWCNT enhanced adhesive patches to environmental degradation is percolation or material system dependent. The incorporation of MWCNTs into an epoxy patch may mediate the galvanic effect between substrate/patch, but also enhances localised degradation phenomena into the polymer matrix. The introduction of 0·1 wt-%MWCNTs positively affects both the galvanic and environmental durability of the adhesive, whereas higher contents adversely affect its behaviour suggesting a percolation threshold between 0·1 and 0·5 wt-%CNT, which, however, is system dependent.