Therefore, the adhesion of Arabic gum to coating can directly depend on the clearcoat surface energy (the balance of hydrophilicity and hydrophobicity).
The greater exposure time of Arabic gum in the xenon test caused more cracks to be shorter and narrower, compared with the samples exposed to 100 h of xenon.
Therefore, the rate of stress applied to the clearcoat during drying of the Arabic gum decreases.
In order to compare the irreversible effects of this kind of degradation with those of other types, the surface morphology of the coatings exposed to Arabic gum and different xenon testing conditions (not exposed to Arabic gum) was studied using AFM microscope images as shown in Fig.
In addition, by comparing the surface morphology and roughness of the sample exposed to Arabic gum and 300 h of xenon testing to those of the one exposed very much longer (even for 1000 h of xenon), a greater surface roughness can be seen.
Effect of Arabic gum on clearcoat chemical structure
This can demonstrate a greater etching performed by Arabic gum on Cl-2.
The stress which Arabic gum can impose on clearcoats during its drying process can affect its mechanical properties.
2 and Table 1, the significant effect of Arabic gum on the mechanical properties of clearcoats can be observed.
However, the lower gloss and DOI retentions were observed for Cl-2 (exposed to Arabic gum at 300 h of xenon).
11, the results of a biologically degraded coating exposed to Arabic gum are shown.