DEFECTS IN SOLVENT-FREE ORGANIC COATINGS STUDIED BY ATOMIC-FORCE MICROSCOPY, SCANNING ACOUSTIC MICROSCOPY, AND CONFOCAL LASER MICROSCOPY

Defects in transparent, solvent-free vinyl ether, and allyl ether male ate-functional coatings have been studied using conventional optical m icroscopy, scanning electron microscopy, atomic force microscopy, scan ning acoustic microscopy, and confocal laser microscopy. Vinyl ether f ilms with different curing rates and allyl ether films with different crosslink densities were prepared, and the number and appearance of de fects present in the films were compared. The varying curing rates wer e achieved by using different initiators, whereas the changes in cross link density were obtained by using monomers with different functional ities. Defects, such as craters and surface crumpling, were observed. Higher curing rates and increased crosslink densities were both found to promote the formation of defects. Atomic force microscopy, scanning acoustic microscopy, and confocal laser microscopy proved to be usefu l techniques in the characterization of organic coatings, with the lat ter being particularly well suited for viewing the interior of transpa rent coatings.