Polyacrylic Acid Copolymers as Adhesion‐Adapted Model Materials for Cleaning Tests

Abstract

For cleaning tests, which are important in many industrial processes, there are no test contaminations with which geometry‐independent homogeneous films can be produced. Polymer films can fill this gap when they are able to mimic the properties of reference contaminants. For this purpose, acrylic acid (AA) copolymers are prepared by conventional atom transfer radical copolymerization and subsequent acidolysis of the tert‐butyl acrylate (tBA) prepolymers. In this way polarity and adhesion can be adjusted by the amount of carboxy groups in the polymer. Dynamic contact angle measurements show that the advancing contact angle of acrylic acid/methyl(meth)acrylate statistical copolymer layers increase with decreasing carboxy group content. Cleaning experiments show accordingly that the amount of residual polymer of coatings made from these polymers is dependent on the absolute number of adhesive carboxy groups in the polymer. Therefore, for an adaption of the polymer layers to hydrophilic reference contaminants it is necessary to incorporate additional hydrophilic monomer components into the polymers, which lead to lower contact angles but also stronger adhesion of the layers. Hence, it is shown that the chosen polymer concept is delivering the leverages to adjust the properties of appropriate test contaminants.