Sensing of dispersion and adhesion by 2D Electrical Resistance (ER) mapping of CNT in polyurethane nanocomposites for aircraft topcoat

Sensing of dispersion and adhesion of PU type aircraft topcoat layer for LSP (Lightning Strike Protection) was evaluated by 2 dimensional (2D) electrical resistance (ER) mapping with different treatment times and multi-wall carbon nanotube (MWCNT) weight fractions. Conductive MWCNT was treated using hydrogen peroxide to improve dispersion in polyurethane (PU) type paint for several days. After treatment processing, MWCNT was dispersed in PU type coating solution using sonication dispersion method. CNT/PU coating solution was applied on the aircraft surface of carbon fiber reinforced epoxy composite (CFRC) using spray method. Static contact angle was performed using 4 types of solvents to calculate the work of adhesion between CNT/PU coating layer and CFRC surface. Surface ER of MWCNT added PU coating layer was measured to determine MWCNT dispersion. Visualization of MWCNT dispersion exhibited using 2-D ER mapping, whereas adhesion between MWCNT/PU coating layer and CFRC was evaluated via cross hatched cut test. The optimized condition of MWCNT treatment time and MWCNT weight fraction was found intensively.