Relationship Between the Surface Topology Observed by AFM And The Properties of Waterborne Polyurethane Coatings

摘要

Atomic force microscopy (AFM) was used to image the surface of the coatings made of waterborne polyurethanesand poly(acrylic urethane)s. Tapping-mode AFM observations were performed under the air and the water-soakedcondition.Degree of dispersion particle coalescence was clearly observed by tapping-mode AFM. It was shown that the degreeof coalescence depends on several factors such as raw materials, size of dispersion particle, temperature, and whether anassisting agent was used or not. It is known that the properties of the waterborne polyurethane coatings, such as physicalstrength, water-resistance and adhesiveness to base materials, were affected by the factors like described above.Through this investigation, the degree of coalescence is found to have a relationship to the surface properties. Thewell-coalesced coatings represented good physical properties and water-resistance. On the other hand, poor water-resistancethat is swelling of coating was observed on the coatings having nano-ordered rough surface of which the unevennesscorresponds to the residues of dispersion particles.