The influence of basecoat pigmentation on chemical structure and surface topology of automotive clearcoats during weathering

The present study aims at elucidating the effect of basecoat pigmentation on the chemical structure and surface topology of its attached clearcoat during weathering exposure. Two extremes of differently behaviored basecoat pigmentations (i.e. silver and black) were chosen. Different analyses such as FTIR, ATR, surface energy measurements and AFM were carried out on such coatings after they were subjected to accelerated weathering conditions. It was found that the black basecoat procured more post-curing reactions to the attached clearcoat at initial weathering times, while the silver basecoat induced higher degrees of photodegradations during the whole time of weathering. Such inductions were attributed to the inherent absorptive or reflective behavior of the black or the silver basecoats toward incident radiation.

► This work illustrates how basecoat pigmentation affects the chemical and surface structure of an attached clearcoat.
► Two extreme differently behaviored basecoat pigmentations (i.e. silver and black) were chosen.
► It was found that the black basecoat procured more post-curing reactions to the attached clearcoat at initial weathering times.
► It was found that the silver basecoat induced higher degrees of photodegradations during the whole time of weathering.