POLYMER ENGINEERING AND SCIENCE, no.4, pp.2106-2118, 2025 (SCI-Expanded)
Among commercial polymer materials, polypropylene (PP) is the most preferred in the world. Low-density materials such as polymers and polymer composites are increasingly used to produce lighter structures. In the automotive industry, these parts are used for painting. Due to the non-polar surface chemistry of PP, PP surfaces have low surface energy, which causes weak bonds in coating, painting, and bonding processes. Therefore, various physical and chemical processes are used to increase the surface energy of PP first, and then the surface is prepared with a primer before painting. However, the primer material and surface treatments used have disadvantages such as extra cost, being harmful to the environment, and the use of fossil fuels. Atmospheric pressure plasma (APP) surface treatment has recently become an alternative to traditional methods. In this study, the chemical and physical changes caused by APP surface treatment on PP surfaces were examined, the effects of process parameters were investigated, and the paintability of surfaces with and without primer was investigated.Highlights Primerless painting feasibility per standards is under investigation. Eco-friendly alternatives to traditional pre-paint treatments are under study. Polypropylene surface properties' effects on painting are under study. Optimal atmospheric pressure plasma parameters for painting are determined.