Investigation of effects of extreme environment conditions on multiwall carbon nanotube‐epoxy adhesive and adhesive joints

Abstract

AbstractMechanical and thermal properties of epoxy‐multiwall carbon nanotubes (MWCNTs) at different fractions (0.0, 0.25, 0.5, and 1.0 wt%) were investigated. The dispersion of the nanotubes in an epoxy adhesive commonly used in an automotive application was performed using a grease worker. This device has a perforated plate, able to produce mechanical shear. To investigate the behavior of adhesive‐carbon nanotubes mixtures and the bonding performance, four groups were prepared using two different perforated plates, P1 and P2. All MWCNT‐epoxy were submitted to extreme environmental conditions, resumed as reference (non‐aged), 500 h at 100°C, 500 h at 95% of relative humidity at 40°C, and 500 h under salt spray. A reduction in glass transition temperature was observed with the addition of the nanofiller and no increases on statistic heat‐resistant index temperature were noticed in MWCNT‐epoxy produced using both plates. Changes in the peaks at 3300, 1510, and 835 cm−1 after aging were seen in infrared spectra. The MWCNT addition to pure epoxy increased the apparent shear strength by 14% using P1. In P2, which has the mechanical shear greater by a factor of 2, no significant differences were observed, due to defects and agglomeration of MWCNTs observed by image analysis.