The impact of baking conditions on physico-chemical characteristics influencing topography and appearance aspects of polyurethane coatings

The appearance aspects of an electrodeposited polyurethane-based coating as a function of baking condition were investigated. Specular gloss and color was measured as a mean to trace the changes of the surface topography due to baking conditions. Atomic force microscopy combined with FTIR spectroscopic investigations showed that the shrinkage occurred due to the high baking temperature results in surface roughness. Films baked at higher temperature form higher-Tg networks. The color was changed to yellow as the baking temperature was raised.