Comprehensive mechanical evaluation of carbon black/polyurethane nanocomposite coating compounded through ultrasonication method

Effect of the presence of nano sized carbon black (CB) as pigment on mechanical and electrical properties of polyurethane/CB nanocomposite coatings compounded through ultrasonication process was studied. The amount of CB in resin was 0, 1, 3 and 5 Wt. %. Abrasion resistance, scratch resistance, pendulum hardness, impact resistance, mandrel bending, electrical conductivity, cupping and adhesion tests were performed on the resultant films. While all samples were measured in the range on 19-24 micrometers thickness, it was found that the cupping, mandrel bending and impact resistance of the films containing 3 and 5 wt. % of CB were slightly decreased. On the other hand, abrasion resistance, pendulum hardness and scratch resistance were strongly increased with increasing of CB contents. Also there was no considerable change between the properties of coatings containing 0 and 1 wt% of CB. Adhesion measurement via tape test revealed that CB concentration had no significant effect on adhesion of the nanocomposite coatings. Furthermore, the electrical conductivity of nanocomposite was linearly increased with increment of the CB contents