Study of an inorganic-organic hybrid coating using FTIR microscopy imaging

C. DEYÁ; P. OGILBY; L. POULSEN

Seggauberg, Austria

Simposio; 17th European Symposium on Polymer Spectroscopy (ESOPS 2007); 2007

Austrian Centre for Electron Microscopy and Nanoanalysis

Hybrid inorganic-organic systems based on sol-gel chemistry are rapidly entering the market for functional coatings and are often identified as nanotechnology products. Their hybrid structure allows for the optimization of easy-clean or anti-corrosion properties as well as mechanical properties. However, simultaneous cross-linking in both the organic and inorganic moieties makes the curing kinetics more complex and the performance of the coating very sensitive to curing-dependent external factors such as humidity, temperature and curing time. The need to follow and understand the cross-linking processes under a range of conditions is therefore imperative. In this paper, we study the reactions that occur in a complex inorganic-organic hybrid system based on silane and epoxy chemistry. The main components of the system are a hydrolysed epoxy silane, bisphenol A and an amino silane. Cross-linking of the organic moieties was followed in-situ after application to an aluminium surface by FT-IR microscopy. Experiments were performed both without and with simultaneous inorganic cross-linking. Interestingly, FT-IR imaging of the coated surface indicates an inhomogeneous spatial distribution of reaction rates leading to domains with significantly different curing degrees. Controlling the degree of this inhomogeneity is ultimately important for the properties of the coating.