Thadeus Schauer

Protection of iron against corrosion with polyaniline primers

The corrosion protection of iron with polyaniline primer was investigated. It was found that the protection takes place in three consecutive phases: conversion of original iron oxides, the active corrosion protection action of a conductive polyaniline form due to the separation of partial cathodic and anodic corrosion processes, and the action of a non-conductive form of polyaniline. The features of these separate phases and the role of a top coat were especially considered.

Evaluation of the delamination of coatings with scanning reference electrode technique

On the basis of the scanning reference electrode technique (SRET), a new laboratory test for the evaluation of the delamination resistance of coatings was developed. With the optimized SRET it is possible to perform screening tests and discriminate coatings according to their delamination resistance within a relatively short period of loading time.

Evaluation of corrosion and protection of coated metals with local ion concentration technique (LICT)

Abstract Local ion concentration technique (LICT) is a new method of measuring pH and ion concentration with high spatial resolution in thin electroytic layers or small volumes. LICT can be used to follow pH changes in corrosive medium during corrosion of metals and degradation of organic coatings. The data can be used to elucidate process mechanisms and to evaluate the protective action of coatings. In this paper, we present the setup and the components of the LICT instrument. Furthermore, we demonstrate the construction of a metal–metal oxide pH microsensor and we compare the effect of aging on sputtered and electrochemically formed iridium–iridium oxide electrodes. Applications for these sensors are discussed.

Synthesis and properties of hydrophobically modified water-borne polymers for pigment stabilization

Abstract Some aspects of the molecular design of pigment stabilizers are discussed. The approach of employing copolymers with pigment-affine segments and matrix-affine segments will be particularly addressed. First experimental results obtained with amphiphilic block copolymers and amphiphilic graft copolymers with similar overall composition with regard to polar and relatively non-polar blocks of, e.g. polar backbone and relatively non-polar grafts will be presented. The comparison between the poly(acrylic acid)-polystyrene block copolymer and the graft copolymer with poly(acrylic acid) backbone and polystyrene grafts showed a similar stabilization of TiO 2 in water.

Bleeding of organic pigments in coatings and its inhibition

SummariesThe bleeding effect of organic pigments was investigated using colour measurement. In the case of the treated surfaces of the test and top coating, the bleeding kinetics were diffusion-controlled (Fickian process).It was also found that the inhibition of bleeding was possible if the pigment was treated with a suitable polymer.RésuméL’effet du saignement des pigments organiques a été investigué en utilisant des mesures de la couleur. Dans le cas des surfaces traitées pour le test et celui de la couche de finition, la cinétique du saignement était contrôlée vis à vis de sa diffusion (méthode de Fick).Il a aussi été trouvé qu’il était possible d’inhiber le saignement en utilisant des pigments traités avec un polymère convenable.ZusammenfassungDas Ausbluten organischer Pigmente wurde mit Hilfe von Farbmessungen untersucht. Es zeigte sich, dass dieser Effekt unter den gewählten Testparametern diffusionskontrolliert (Fick’scher Prozess) ist. Es war darüber hinaus möglich durch Behandlung des Pigments mit einem geeigneten Polymer den Effekt zu inhibieren.